December 11, 2018
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Glass Blowing Terms and Techiques



Alien Skin (Bubble Trap)

This is a very neat technique we love here at Elev8 Premier. There are a lot of names for this. Its a form of bubble trap, sleeving and fuming.

What is alien skin to us – WOW is how this makes us feel when we see it, so it must be out of this world.  How it sometimes made is a dark tube, maybe jet black is used.  Sometimes a blower will make their won coil pot tube. Once the blower has the colored tube they will roll it on a frog or take a knife and put lines into it. Then the blower will fume the glass with silver and or gold. We prefer to get that perfect fume of silver mixed with gold to get that amazing green color. Once you have this the blower takes it and puts it inside a clear tube of glass and then removes the air around it. This traps small air bubbles in the glass, hence why we call it bubble trap also.



This is a tall ancient Greek or Roman jar with two handles and a narrow neck. Glass blowers use the term to refer to a classical vase design.


Annealer (Lehr)

Glass works made from glass that have been super heated need to cool very slowly down to room temperature.  If it cools too fast the glass will get stresses and it will crack.  These machines are large ovens or kilns used to slowly cool the glass very slowly down to room temperature.



The process of letting the glass cool very slowly so that internal stresses are removed and the glass is tougher than it was.

What annealing is to us – This can mean a lot of things to us in the glass blowing world, yet still means the same thing.  We anneal the glass in order to remove the stress. The stress is built up in the glass as some parts are hotter than others and the molecules move differently depending if they were hotter or cooler. What we are doing when we anneal is to bring all the molecules up to the same temperature so they all dance the same. This is not actually annealing though. The annealing starts as we cool the glass. The slower the better.  This allows all the molecules to cool at the same rate. This way the molecules arrange in a more uniform way. The thicker the glass the slower the glass much cool to become fully annealed. Borosilicate glass anneals at 1050 F. Soft glass (Moretti) anneals at 960 F.

Borosilicate Ramp up – 38 min ambient to 1050F
Soak – 15 min at 1050F
Slow Cool – 30 min to 910F
Fast Cool – 47 min to ambient
Soft Glass Ramp up – 3 hours ambient to 960F
Soak – 1 hour 30 minutes at 960F
Slow Cool – 2 hours to 810F
Fast Cool – 1 hour to ambient



This refers to the conditions within the torch flame. The atmosphere can be described as oxidizing (High in Oxygen) or reducing (Low in Oxygen).

flame atmosphers

Oxidizing Flame – is the flame produced when an excessive amount of oxygen is used. When the amount of oxygen increases, the flame shortens, its color darkens, and it begins to hiss and roar. As its name suggests, it oxidizes the glass surface. Some glass colors love to be worked in this flame and others do not.

Reducing Flame – is the flame with low oxygen. It has a yellow or yellowish color due to carbon or hydrocarbons which bind with (or reduce) the oxygen contained in the materials processed with the flame.[1] The reducing flame is also called the carbonizing flame. This is a much cooler flame and some colored glasses love to be worked in this flame.



Special glass that is made with flecks of copper. The copper adds a bit of sparkle to the Venetian style of work and ups the cost to make the glass. Northstar makes a color called Mystery Aventurine.



Hourglass shaped connecting piece commonly seen in Venetian style goblets. The avolio serves as not only a visual element, but also provides a thin spot which makes it easier to use the fork to load the goblet into the kiln.



Batch is the raw materials that are melted into glass. The process of melting batch is called charging and is quite time-consuming; our furnace requires about 9 hours to cook the batch until it is relatively bubble-free. Borosilicate can take up to 3 days to get bubble free.



A blank is a small hollow glass cylinder made using a specific color technique. Several blanks can be made from one large bubble, then each blank can be used to make a single piece. The white striped blank is used for making mezzo-filigree.


Bleb –

A bleb is that little bit of glass left on the end of the tube when you split a tube or take the glass off when you close the end.  This can be removed with a glass rod to make the wall thickness evener.  The bleb will cause the glass to gather in that spot if not removed.

Bead Release

Usually this is a consistency of mud. Used to put on mandrels so that the glass can be taken off of the metal rod (mandrel). Once it is on the rod it is dried so it is hard and the glass can be layered on top of it.


Billow (Condenser)

This is where the tube of glass shrinks or condenses in.


Body Wrap

A body wrap is a single thread of glass that is applied to the outside of a vessel. It is very difficult to put one of these on and have it line up properly.


Borosilicate Glass

A type of glass with silica and boron-trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion (~3 × 10−6 K−1 at 20 °C), making them resistant to thermal shock, more so than any other common glass. Such glass is less subject to thermal stress and is commonly used for the construction of reagent bottles

In addition to quartz, sodium carbonate, and aluminium oxide traditionally used in glass making, boron is used in the manufacture of borosilicate glass. The composition of low-expansion borosilicate glass, such as those laboratory glasses mentioned above, is approximately 80% silica, 13% boric oxide, 4% sodium oxide and 2–3% aluminium oxide. Though more difficult to make than traditional glass due to the high melting temperature required, it is economical to produce. Its superior durability, chemical and heat resistance finds use in chemical laboratory equipment, cookware, lighting, and in certain kinds of windows.



A bowl refers to the top part of a goblet, the part that you drink from. There are many different shapes for bowls, used for different kinds of drinks.



The heat source of the flameworker. It usually runs on gas and oxygen or air. It consists of a head that contains many orifices to distribute and direct the flame, a body where the gas is passed up to the head, and a valve assembly where the proportions of the gas/oxygen mix and volume are controlled.



The application of one layer of glass over another, usually to achieve a layered effect for graal or cameo glass.


Coefficient of Expansion (COE)

The relative amount that a material will expand when heated.


Coil Pot

This is an old school technique a blower uses to make their own tubing.  Usually made on a blow tube with a colored stick of glass.

Coil Pot by a blower – What you do here is get a blow tube, we usually use a 12mm tube.   Flare the end open and then get you some of your favorite colored rod of glass.  Heat this rod up and when it becomes hot and malleable you will lay it around the blow tube.  You will build this up and it will look like what a potter does with clay when they make a pot.  Hence the name coil pot.  Once you have this built up you can melt it all together into a bubble and then you can make a tube or what ever you want with it.


Color Bar

Mostly only in soft glass color comes in the form of bar. The major manufacturers of soft glass color bar are Reichenbach, Kugler, Zimmerman and Gaffer. The process of making these involves adding metal oxides and other toxic ingredients to crucibles of molten glass, and then pulling the glass out and rolling it into bars.



Different glasses that have the same COE are said to be compatible. This means that they can be joined together while hot without breaking apart when cool.


Cracking Off

The technique of breaking off the punti or rod that has been used as a handle during the forming process.


Cuts and Burns

These can be avoided with common sense and care. The most common minor burns occur when someone picks up the end of a glass rod or tube, forgetting that it is hot. A simple system, such as always laying the hot end of a rod away from you, can help you remember which end to grab.

Arrange your work area so that you never have to reach in front of your torch to get a tool or piece of glass. Choose your work clothes carefully, avoiding synthetic fibers, long loose sleeves, and shirts with open pockets or pants with folded cuffs.

Burns can be treated with ice, aloe vera sap, cold cider vinegar, or a variety of home remedies. Treat your injuries with respect; serious cuts or burns may require professional medical attention.



It is the crystallization in a formerly crystal-free (amorphous) glass

Devit by a blower – This is that old man look, the part of the glass that does not shine. Its is like small tiny wrinkles, or it can be whitish. There is a lot that causes this. Sometimes in boro it can be fire polished out, sometimes its over and you have to sand blast the glass. (Ever wonder why that piece was actually sandblasted? Well this could be the reason why). Anyways this usually happens on a piece of glass that has been over worked, or has gotten lots of stress. Now sometimes we call a spot devit, even when it is not. Rather it is a spot that has lots of stress from a bend or something and should have been fire polished. Either way not what we are looking for in the glass game. If it is true devit, well then its stuck there and can not be fire polished off. One neat technique that sometimes can help solve this is basic table salt. I do not know if you burn too much sodium out of the glass, but if you pour some salt in the flame and let the burn of the salt hit the glass, it can make the devit go away. Just try to avoid it all together.


Dichroic Glass

Basically glass which has a thin metal coating applied to give it a reflective tint.

Dichro by a blower – So thanks to NASA we have this really neat glass to play with that is all sparkly. What they do is some how they vaporize these metals in a vacuum and they then adhere to the glass sometimes only 1 to a few molecules thick. Different kinds of metals give us different colors with nearly 45 as of now. Okay, so now we have this glass with metal on it right, but we have to not burn it off and get it trapped between glass. What the blower must do is cover or back the glass with clear or a color. Backing the metal with a color adds yet another dimension to the glass! Once the blower makes that glass, he/she then takes it and lays it inside another piece of glass. Now there are a million ways to do this, but this is one of the most common today.
5 tips for working Dichroic Tubing


Double Disappearing Weld (Jesus Weld)

This is a special technique commonly used with making complex water filters such as a Kleincycler and Recycler. This is where a tube is joined to the main body of the glass piece, by carefully glassblowing a bubble in between the two pieces.

double weld

A blowers point of view – This weld is extremely difficult if you do not know what you are doing. Once you know you know. The trick is to get one part of the tube welded so that you can blow into the tube and the body of the piece you are working on. You want the tube to finish about 5-10mm from the body. Then with the torch heat up the tube and body so when you blow you can blow two bubble that will touch each other. When you do this you want them to touch and touch to make about a 5-7mm say weld. Then you come in and heat up the weld and blow out lightly. As glass wants to thicken up it will gather and pull from the inside make the two bubbles that touched a hole. Now you did it!

About 55 sec. in is where the middle gives away and a hole is made.



The technique of pulling a piece of hot glass to make it narrower.  We also do the normal drawing if we are making something big so we can better conceptualize it.



Our basic definition of this is a metal forming process that allows metal to form on something. The process is done in very clean water. There is a piece of metal and some current that is put into this water solution. When there is current the electrons move from one thing to the other.


Eye Protection

Eye protection is very important in lampworking, for two reasons.

First, glass can sometimes shatter when placed directly in the flame, and you must protect your eyes from flying glass fragments. Goggles or glasses with side shields are good for this.

You must also protect your eyes from potentially damaging Ultraviolet and Infrared rays, which are emitted when you melt glass in a flame. For many years, the standard eye protection for lampworkers has been “didymium” glasses, which have the additional feature of filtering out the distracting yellow glare given off by molten glass.

In recent years other types of protective eyewear have become available, some of which are superior to traditional didymium glasses. The type of protective eyewear that is right for you depends on the type of glasswork you will be doing. For instance, making beads would give off less radiation than working a large piece of borosilicate tubing, which in turn gives off less than melting fused quartz. Also, different people may have different sensitivity.

Please protect your eyes. Check with your optometrist and other reliable sources for more information on choosing eye protection.



A rod of glass that has color in the middle and clear around the outside


Filigran by a blower– What a neat technique! There are a few ways to make this. First you can take a clear tube that is just larger than the color rod. Put the color rod into the tube and get all the air out.  You now have a filigrana. You can also accomplish this by coating the colored rod with clear glass.


Fire Polish

Simply when you take fire and polish an end of glass. This is used to make the end of the glass shiny if it was cut or cracked off. It also makes the glass smooth so it will not cut you. The tube on the right has been fire polished, while the tube on the end was scored and cracked leaving a sharp end that could CUT you. These are plain dangerous in the shop. They are really really dangerous if they are a blow tube. Fire cut or fire polish your ends.



A flame working technique where the finished piece is reheated in a bushy, relatively cool flame to relax the stresses built up in it during the construction process. This is usually used only on small pieces and is generally regarded as a temporary measure for work that is to be properly annealed later on.



Any technique where the flame is used to burn apart two pieces of rod or tubing. You cut the glass with a flame baby!



Also known as lampworking or lamp-blowing. The technique of heating, melting and forming glass rods and tubes using a flame generated by a burner or torch.



This when a blower takes a tube and heats the end up. Then they use a tool or G’forces to open the end of the tube.


Fluorescent Light Transitional Glass (CFL glass)

This is glass that changes color when it is under fluorescent light. The minerals that go into this are TOP SECRET. There are a lot of new colors coming out that change this way. We are not sure why they call it CFL glass as CFL stands for (compact fluorescent light), but ya this is the industry terms.



Glass that is broke down very small so that is looks like sand. This can be from near powder to large 8mm chunks. Most commonly used is small to large that is about 1-4mm.



This glass technique is one of the first basic techniques learned by a blower. It is very simple and silver is inexpensive for what it does. Gold is a little more costly, but it takes fuming to the next level.

Silver Fuming

Silver Fuming – The glass must be hot in order for the silver to stick to it. Preheat you piece of glass using nearly any size tube or rod, you can even fume colored glass. First you must also have a rod of glass with a piece of silver on it. To do this you heat up the glass 5-10mm rod with a small small piece of silver cut and laying on your graphite. I prefer about a 6mm piece of clear glass. If your silver does not stick the first time heat the glass up again and and press on the silver until the silver sticks to the glass. Once you have this not back to that piece of glass you want to fume, again make sure it is hot. How I prefer to fume is turn my torch down to a small small neutral almost reduction flame. Then I put the silver in there and it will start to smoke, but sometimes is splatters first, I do not like this unless I am using it for a special technique. So I let it splatter than once it does that I then put my glass I want to fume into the flame and spin it. Now you can do too much here, only cover it.  If you do too much you can burn it off with an oxidizing flame. Fuming is all about the application. Ones you have your glass fumed with silver you can do all sorts of things with it.


Gold Fuming – Gold takes fuming to the next level. Gold is best fumed on top of silver, I prefer just a slight silver fume under the gold. This also is what gets some super dope greens, what I just love!  To get the gold to fume you need a little hotter more oxidizing flame. I use the same little flame for silver, just turn up the oxygen a little and it will get the gold hot enough to fume.  Once you have the glass fumed you can sleeve it, draw clear lines or dot it up. You can also fume the outside or inside of the glass. Both give amazing and unique effects.  Did you know at a microscopic level gold is red. The first nano technology was done by a glass artists many, many moons ago.


Fused Quartz

quartz glass

Glass consisting of silica in amorphous (non-crystalline) form. It differs from traditional glasses in containing no other ingredients, which are typically added to glass to lower the melt temperature. Although the terms quartz and fused silica are used interchangeably, the fundamental structures and creation of each glass differ. Fused silica, therefore, has high working and melting temperatures. The optical and thermal properties of fused quartz are superior to those of other types of glass due to its purity. For these reasons, it finds use in situations such as semiconductor fabrication and laboratory equipment. It transmits ultraviolet better than other glasses, so is used to make lenses and optics for the ultraviolet spectrum. Its low coefficient of thermal expansion also makes it a useful material for precision mirror substrates.

Quartz by a blower – This is typically what your bangers are made of. Really any glass you will heat up over and over and cool down rapidly by putting oils on the glass.



An oven or kiln used when making complicated work made from many parts. The parts are kept warm in the garage or kiln until needed. For example, when making complicated rigs, goblets, or just big things, parts are made and then stored in the garage. For a goblet he foot is made, and then the stem is brought from the garage and attached. Finally, the bowl is brought and attached to the top of the goblet. For soft glass the right side (cold side) of the garage is kept around annealing temperature (900 F), the left side is usually around 1050 F. For borosilicate the garage temperature can be set at 980 for less intricate pieces and 1080 for more complicated pieces.



Any mass of molten glass collected on the end of a punti or rod.  This is usually accomplished by holding the hot part of the rod up and letting it fall back onto itself.


Glass Forums

This is where blowers will go for information from other blowers. Here are a few we have found and like.

Lampwork Etc.


Glass Storage

This is a place or thing you store your glass in.


Ground Glass Joints

These are what you see on all the glass water pipes and rigs. They have been around for a very long time. Many of the joints that come from Germany are made on a machine. Many of the joints that come from China are made by hand. Both are great, just one puts more people to work. The USA has also started making joints in clear, while many of the top artists make their own joints.


Hard Glass

A common name for borosilicate glass. It has a COE of approximately 33.




Heady Glass

Heady Glass is a style of glass that is incredibly artistic. By incorporating lots of color, as well as advanced glassblowing techniques, glass made in the style is very much one-of-a-kind! Many glassblowers, such as those in our Elev8 Glass Studio, specialize in particular techniques, and do custom work to make a name for themselves.


Health and Safety

Like any craft or hobby, glass working has some inherent risk of injury to the artist. As interest in lampworking has increased, it has become clear that general information on potential health and safety risks would be useful.

The following information is intended to increase your enjoyment of lamp working, while adding to your awareness and helping you reduce your exposure to potential hazards. These suggestions have been prepared and reviewed by a group of experienced lamp workers. This is not intended to be a complete list of all hazards associated with lamp working, other hazards may exist.


Incalmo (Encalmo)

Incalmo is the advanced technique of joining two glass bubbles of different color together. Typically, one bubble is opened into a cup shape, and then attached to a punty, and the other is opened into a cylinder on the end of the pipe. The cup is then joined on the cylinder to make a two color piece.


Inside Out Work

This is glass that has a layer of clear on top of it. This can be accomplished with a few techniques such as puff and stuff, flipping, or just opening a tube and drawing inside. It can also be as easy as dumping frit inside a tube and melting it in.


Iridizing or Iridized Glass

iridized glass

A technique involving spraying hot glass with metallic salts to give and iridescent finish. Requires very good ventilation.


Klein Bottle

An example of a non-orientable surface; it is a two-dimensional manifold against which a system for determining a normal vector cannot be consistently defined. Informally, it is a one-sided surface which, if traveled upon, could be followed back to the point of origin while flipping the traveler upside down. Other related non-orientable objects include the Möbius strip and the real projective plane. Whereas a Möbius strip is a surface with boundary, a Klein bottle has no boundary (for comparison, a sphere is an orientable surface with no boundary).

The Klein bottle was first described in 1882 by the German mathematician Felix Klein. It may have been originally named the Kleinsche Fläche (“Klein surface”) and then misinterpreted as Kleinsche Flasche (“Klein bottle”), which ultimately may have led to the adoption of this term in the German language as well.


Line Work (Lined Tubing, Colored Tubing)

Line work can mean a lot of different things. We believe line work is a tube of glass that is colored with rods of glass. This line work tubing is usually made into switch balls and then put back together. It is made by a number of techniques. These techniques include but are not limited to:

  1. Flaring open and drawing the lines in with stringers?
    1. This is done by opening up a tube of glass and flaring it open. Then pull stringers about 2mm thick. You will then draw lines down the flared tube. You will notice the open end is a larger diamter from the side welded to the blow tube. This will cause you to make a “V” patern as you color the glass. This is ok and you will not even see it. Melt it down and you have some line work tubing. This also makes great tube work for terminations as you have just clear glass over color.
  2. Stick Stack:
    1. This techniques is when you place rods of color inside a tube of clear glass. The way we do it at Elev8 Premier is that we take a 50mm tube and a 1 inch graphite rod. We cut the color down to size and lay it around the graphite. Put a rubber band around the glass and graphite. Then you will insert this into the clear glass. Once inserted you will remove the rubber band and start to melt it down. Once you get some of the color to stick to the clear you are good. You can remove the graphite and work it all down into 1 piece of glass. You know have a line work tube of glass. We prefer this method as one of our favorites as you tube is clear over color and you can get some great terminations.
  3. Vac Stack:
    1. Yep and this is kinda what the big boys do to go fast, have a lot of color and get some weight. So how we do it here at Elev8 Premier is we use a 80mm x 9mm clear tube of glass. Then we put 26 rods of color around a 45mm heavy wall tube of clear. We put the 45mm inside the 80mm tube, then we lay the rods in between these. Once all the color is in there we begin to melt it. Pull and you now have line work tubing. This is great to work with, nice and thick and just has a lot of lines of color. One thing you have to have good skill is on your terminations. This makes great line work, but the tube (looking at the open end) out is clear, then color then the inside is clear. What this can cause is when you terminate that clear will pull through and make like a fish eye. You need to have your termination skill set on point before you attempt terminations on this kind of line work tubing.



A round piece of glass. Usually with some kind of artistic style to it. They can be from a small 1/4 inch piece to a massive 8 inch the size of a bowling ball.



This is a technique that is loved by Elev8 Premier, particularly Steve. Glass does not get wet enough so that the color can move through, so the artist must lay the colors he/she wants on top of their main color. Then mix it in so it appears to be marbled, well I guess it is if it looks like it.


Mariah (Maria)

This is where he blower heats up a tube and pushed it together to make a ridge or narrow band. It makes a ring around the tube.


Marver (Marver Pad)

This is a process of shaping the glass with a tool. Also it is a tool used in glassblowing. It generally is made of a polished steel, brass, or graphite surface attached to a metal or wooden table.


Melting Point

The temperature below which glass acts as a solid and above which it can be shaped.


Metal Oxides

When glass color is made, the metal oxides are stable and “in solution”, anytime you work with the glass, in any manner, you may be breaking open “the solution” and exposed to the metal oxides. This is a list of some of the metal oxides that may, or may not, be contained in the colored glass rods we sell, it is not intended to be a complete list: Iron Oxide, Chromium, Sulfur, Calcium, Manganese, Manganese Dioxide, Cobalt, Arsenic, Potash, Copper Oxide, Nickel, Chromium, Tin Oxide, Cadmium, Titanium, Uranium, Didymium, Selenium, Copper, Gold, & Silver.



A combination of the Italian words “mille” (thousand) and “fiori” (flowers).

Milli by a blower – Ok so all those picture chips, those are what we call millies. They started long ago with basic shapes turned to flowers. Now the technique is used to make all kinds of pictures. This is a very very time consuming technique. Lauren Stump is one of the greatest milli makers of our time.


Murrine (Murrina)

Colored patterns or images made in a glass cane that are revealed when the cane is cut into thin cross-sections. Murrine can be made in infinite designs from simple circular or square patterns to complex detailed designs to even portraits of people. One familiar style is the flower or star shape which, when used together in large numbers from a number of different canes is called millefiori.


Neutral Flame

This is the hottest flame on the torch. It has a good burn of the propane and not too much oxygen.

How to set a neutral flame

Glass Alchemy recommends you always work with a neutral flame (saving reduction for the final step)—it helps maintain consistency and vibrancy in your work and eliminates the cracking of chrome colors. The neutral flame test in borosilicate was developed at Glass Alchemy with Amazon Night, 987 and is now an industry standard. No flame will ever be neutral from base to tip and each torch has a different neutral zone. The area closest to the torch face tends to be reducing so don’t work too close. When properly set, the middle section is neutral and is the ideal flame for working colored borosilicate.

Heat a rod of Amazon Night, 987 until it glows a dull orange; remove from flame and cool. If the rod does not change color, you have a neutral flame!

If the rod is light sky blue1 or has a metallic sheen2 this means the flame is reducing and the propane needs to be decreased.

Note: that the propane to oxygen ratio depends on the torch you are using.

If the rod is sky blue, the flame is very reducing and should be adjusted by decreasing the propane pressure at the regulator (ex: from 4 to 2 pound).

If the rod has a metallic luster, try decreasing the propane on the torch or at the regulator in ¼ pound increments until you are able to heat the rod without a color change.


Northstar Glass

This is the hottest flame on the torch. It has a good burn of the propane and not too much oxygen.


Opals (Gilson Opal)

Opal is one of the world’s most beautiful and precious gemstones, predominantly found in Australia. It is one of only six types of precious gemstones found on planet earth, sharing prestigious company with diamonds, rubies, sapphires, emeralds, and pearls.  You can not use a natural opal in glass. You must use a created opal called a Gilson Opal. The term, “laboratory-grown” means that our products faithfully mirror Mother Nature’s opal. Gilson-Created™ Opals have virtually identical chemical, physical and optical properties as do their naturally-occurring counterparts. The exception is that our lab-grown products are harder and more durable than most of those from nature. We no longer produce Gilson Created opal varieties in rough, uncut volumes, loose stone assortments and in fine jewelry designs. So, if technology is your fascination, beauty and affordability your pursuit…have a look. Click here to learn more about natural opals.


Oxidizing Flame

This occurs when you run your torch with a lot more oxygen than what is needed to burn all the fuel. When you do this the atmosphere is rich in oxygen and with some glass the oxygen atom will actually bond to the glass. Running too much can cause what we call devitrification. Sometimes you do want to run an oxygen rich flame as the oxygen molecule will not adhere to some glass and you want to run it a little cooler.


Percolator (Perc or Diffuser)

This is the thing inside the water pipe that lets the air/smoke/vapor in small bubbles go through the water. These can range from 1 hole in a tube inside the rig/water pipe all the way to a hand sculpted piece or art that lets the air go through it. The more percs there are, the more drag there is usually as the smoke/vapor is going though more water at once and more holes. This does make the smoke/vapor cooler, but a little harder to pull. We will list all the percs we know below.

Perc 1

Perc 2

Perc 3

Perc 4

Perc 5

Perc 6

Perc 7

Perc 8

Perc 9

Perc 10

Perc 11

Perc 12

Perc 13

Perc 14

Perc 15

Perc 16

Ball Perc – Basically they blow a ball and then cut slits in the ball. Then in the cuts the make a tack weld to help break up the air and diffuse better. These take a lot of time to make, but work great!

Beaker Perc – This is a percolator in the shape of a beaker bottom.   The blower makes this shape, then he/she will cut slits in the bottom and then weld it into the water pipe or rig.

Downstem Perc – This is usually the only perc a water pipe gets when its simple. This diffused downstem is made with many small holes. This will make many small bubble that has the vapor or smoke touching more surface area to clean and cool the hit better.

Fountain Perc – This perc usually sits about the main body and sometimes they stack these, I have seen up to 4 tall in sections. Many many slits to diffuse even more and make small fine bubbles. This is an example of one an artist did.

Inline – Invented by HopsGlass many many moons ago. This is kinda the start of all the perc rage.

Inline with Slits – This is a modern inline perc that has slits and then then blower comes back and puts tack welds in the slits to diffuse the air more.

Honeycomb Diffuser – These are basically a disc with as many as 100 or more holes and these are made in a mold. The tiny holes make tiny bubbles when forced through the Honeycomb Diffuser. This increases the amount of interaction between smoke and water. These are a solid choice, and are extremely popular. We love these! They are durable and diffuse so so well!

Frit Disc Diffuser – This type of Diffuser bounds tons of tiny glass fragments called frit together leaving tiny holes in between each fragment. The amount of diffusion on a frit disc is pretty much unbeatable. The smoothness of a frit disc diffuser delivery is unparalleled. One thing we see bad about these is they clog very easy as they perc holes are so so small.

Shower Head Perc – These percs feature slits or holes in order to increase diffusion and filtration. These can range from 3 slits to 50 slits or more.

Spread-Shot Diffuser – OUT OF CONTROL is what this design is. Takes a long time to make but the function is great!

Tree Perc – Tree percs offer a great level of diffusion. The more arms they have the more holes there will be and the more percolation you will get. Each of the arms of a tree perc will usually have slits in the side and either a closed or an open bottom, we like them best when each arm is welded to each other. DO NOT BUY if the arms are not welded to each other. A hit and those arms could break off. The smaller the slits, the more the diffusion and filtration.

Single Stem Perc with Slits – This is one of the most common percs. They work great and are simple and durable. These percs can be made from 1 cut to as many cuts as a blower can cut and put on the percolator.

Vortex Diffuser – This is a disc that is cut at angles. The angles allow the vapor or smoke to swirl inside the water pipe. Many believe this vortex helps to enhance the flavor as it allows more particles to stick to the side of the glass.



glass points

This is a tube of glass pulled down from a larger tube. As you pull the piece of glass off the large tube you pull basically a handle for later. This is the start of a pipe or many things.



Finely ground glass that is a powder.



The process of heating a glass piece from room temperature to a state sufficient to prevent serious shock when plunged into a flame. This can either be done in a kiln or in the backwash of a flame.


Pre-Mix Burner

Any burner that mixes the gases inside the body of the burner prior to ignition.



A temporary glass handle to hold the glass for working it.



A very unique pattern made in glass that has many lines that cross over each other. The more lines the harder it is to make.


Reducing Flame (Reduction)

This is the flame with low oxygen. It has a yellow or yellowish color due to carbon or hydrocarbons which bind with (or reduce) the oxygen contained in the materials processed with the flame. The reducing flame is also called the carburizing flame, since it tends to introduce carbon into the molten metal. This is a cool flame compared to the neutral flame


Respiratory Hazards

Melting glass in a flame produces a number of gasses and vapors that can affect your health. It is important, therefore, to ventilate your work area. At the very least, you should provide “dilution ventilation”, in which a steady stream of air flows across your work area, drawing any vapors or gasses away from your face and out of the room. Windows at opposite ends of your work area, one of which has an exhaust fan, can be an effective form of dilution ventilation. Ideally a window should be open behind, or to your side, to ensure fresh air flow.

Some lampworking operations may require “local exhaust ventilation,” such as a fume hood, to eliminate hazardous or irritating vapors and gases. If you find that you feel slightly short of breath or that you have a headache at the end of a work session, then you can be certain your ventilation is inadequate.

An additional respiratory hazard is posed by glass dust particles you might encounter in your studio or work area. These include powdered “bead release” compounds, the dust stirred up when you work with vermiculite and loose particles of refractory materials such as brick or ceramic-fiber insulation inside your kiln, and especially dust present in frits and powders, or created from cutting, breaking, sanding, grinding or cold working color rods. Dust should be handled with proper safety procedures, including wearing a full tight fitting style, NIOSH certified respirator, with a P100 rating on the cartridge, any time you are creating, or working around glass dust. You do not want to inhale or ingest any glass dust.

Take care not to inhale these irritating and potentially harmful dust particles. Be aware of hazardous dusts that can be stirred up when you are cleaning your studio. You can also use a sweeping compound made for fine particulates, in order to keep the glass dust from rising up off the ground.

Wet down any questionable areas or spills with a spray bottle before wiping with a wet rag, to reduce the chances of inhaling particles. If you sandblast your finished pieces, follow all safety guidelines appropriate to sandblasting.



A disk of glass formed by spinning and flattening an opened bubble.


Scientific Glass

Scientific Glass is borosilicate glass that is made thick with specific shapes, to make glass that is durable, as well as very clean looking. Scientific Glass often includes complex and enamoring percolators, a well defined shape similar to what a scientist would use in their lab, and an overall uncolored, pure style.



This is when you take a scoring knife or diamond wheel and cut into the glass.  This small scratch or cut on the glass makes it so much easier to break the glass, and break it in a clean pattern. There are many different kinds of score tools to help with cracking glass just right.



Small rock, mineral, kiln part or unwanted bubble that is in the glass. Bubbles are not really seeds, and if you have a seed you should remove it.



Silicon is the eighth most common element in the universe by mass. Over 90% of the Earth’s crust is composed of silicate minerals, making silicon the second most abundant element in the Earth’s crust (about 28% by mass) after oxygen. Most silicon is used commercially without being separated, and often with little processing of the natural minerals. Such use includes industrial construction with clays, silica sand, and stone. Silicates are used in Portland cement for mortar and stucco, and mixed with silica sand and gravel to make concrete for walkways, foundations, and roads. They are also used in white ware ceramics such as porcelain, and in traditional quartz-based soda-lime glass and many other specialty glasses. Silicon compounds such as silicon carbide are used as abrasives and components of high-strength ceramics.



Polymers that include any inert, synthetic compound made up of repeating units of siloxane, which is a chain of alternating silicon atoms and oxygen atoms, frequently combined with carbon or hydrogen or both. They are typically heat-resistant and rubber-like, and are used in sealants, adhesives, lubricants, medicine, cooking utensils, and thermal and electrical insulation.



Silicosis is a lung disease caused by breathing in tiny bits of silica, such as those that within glass. This is a major hazard when sandblasting or crushing frit, that should be addressed by wearing an OSHA dust mask rated for hazardous abrasive particles. Over time, exposure to silica particles causes scarring in the lungs, which can harm your ability to breathe.



Slumping glass is a highly technical operation that is subject to many variations, both controlled and uncontrolled. When an item is being slumped in a kiln, the mold over which it is being formed (which can be made of either ceramic, sand or metal) must be coated with a release agent that will stop the molten glass from sticking to the mold. Such release agents, a typical one being boron nitride, give off toxic fumes when they are first heated and must be used in a ventilated area. The glass is cut to the shape of the mold (but slightly larger to allow for shrinkage) and placed on top of it, before the kiln is heated.



To keep glass at a specific temperature for an extended period of time, such as annealing



Sodium Oxide (Na₂O), or common used by glassblowers in firstReference to Sodium Carbonate (Na₂CO₃)


Soft Glass

The most popular glass for lampworking is soda-lime glass, which is available pre-colored. Soda-lime glass is the traditional mix used in blown furnace glass, and lampworking glass rods were originally hand-drawn from the furnace and allowed to cool for use by lampworkers. Today soda-lime, or “soft” glass is manufactured globally, including Italy, Germany, Czech Republic, China and America.

Soft Glass by a blower – This is a lot of things in glass really. They are most all the glass, bottles, high color water pipes, those big dishes, things that Dale Chihuly does.


Strain Point

The strain point is defined as a temperature at which a certain glass viscosity is reached. It is that point at which all movement of the glass molecules has reached a point at which no more strain can be introduced into the hot glass. It is usually about 100 degrees F or so below the annealing temperature. Like all such temperatures it represents some point in the range of such temperatures for a glass family. For example, for Effetre/Moretti glass the annealing temperature is usually listed as 968 degrees F and the strain point about 840 degrees F.



A force exerted on a material, such as the internal stress inside glass caused by uneven heating.



Striking colors are glasses that can be 2 different colors. It has to do with the orientation of the molecules inside the glass, which will change from one state to another on being cooled and re-heated. Transparent reds, oranges and yellows and most opaque pinks for example are striking colors. Usually you strike colors at the last step after shaping a bead, by letting the glass cool and reheating it quickly in the flame so that it takes the shade you want it to be.

By Henry Grimmett

Some glass formulations, such as transparent ruby (colored with copper) and those that are colored with silver, change color when heated or cooled in specific ways. However, the reasons for their color changes aren’t necessarily the same. The term striking has come to refer to any color change in the glass due to heat treatment of some sort. While this terminology is acceptable for lampworking it should be understood that copper and silver glasses undergo very different reactions.

In our Ruby glasses copper is the element responsible for the color change. Copper oxides (Cu2O) are added to the batch and melted. As the glass is melted the Copper molecules and the associated oxygen molecules break apart and join with other molecules in the batch. Rapid cooling of the glass causes these high temperature bonds to become permanent and leaves the glass clear. The magic of the ruby color is that these bonds can be broken at the annealing temperature of the glass and the copper is free to create Cu2O and colloidal Cu particles. (There is some debate whether it is the Cu or the Cu2O that creates the ruby color, however, a combination of the two creates the best effect). Glasses that undergo this type of molecular realignment are what were traditionally referred to as striking colors.

The other type of color change is caused by crystal growth. Glasses such as our Silver Strike series, our Amazon series, and our Chameleon series, can be looked at as having millions of tiny molecules of silver floating around the glass network. These tiny silver particles reflect a yellow wavelength when evenly dispersed through the glass. The fundamental difference between the copper and silver strike is how these particles react to heat. The copper particles free themselves and form individual Cu or Cu2O particles that reflect red light. The more red particles there are, the darker the ruby color. Silver, however, frees itself from the glass and bonds with other free silver particles creating silver crystals of varying size.

The crystal growth process is a function of time and temperature, and can be controlled for the creation of the full spectrum of colors silver can produce. If the glass is subjected to high heat, the silver particles are freed from the glass matrix and move through the glass until subsequent cooling forces them back into the matrix causing the glass to look the same as before it was heated. (Note: Returning to its original rod color takes place in glass that contains only silver. Glasses such as the Amazon and Chameleon series, have nuclei present which allow silver particles to form crystals and prevent them from returning to their original state.) When the glass is cooled, not all of the silver particles make it back into the glass matrix. Upon subsequent heating these homeless silver bits act as nuclei, or places for larger, more stable silver crystals to grow. It is this heating, cooling and reheating process that enables larger crystal growth. The color reflected by the glass is a function of the size of these crystals varying from yellow (small crystals) though purple, blues and greens (large crystals).



This is a small rod of glass that is pulled down to be very fine. Maybe about .5 mm-5 mm thick. These are used for drawing lines on things or used for ratichilios, fillichelios and just those cool lines on inside out work.


Switch Ball

This can be a lot of different piece of glass that are switched from one axis to the other. This will give you two terminations. Many times this is made on line worked tubing to give that wig wag effect that is just so freaking amazing!! This is a very complex piece of glass. Sometimes this is called switch axis because you are switching the axis of the glass. This piece of glass starts sometimes with a 50mm to 80mm piece of clear tubing lined with stripes of glass. It is then sleeved with more clear glass, or striped with clear glass, to make more colored glass. This becomes a large colored tube of glass. This large tube is pulled down to a 10mm-20mm diameter tubing, cut in 2-5 inch lengths. Then wigwagged back and forth to make a wig wag effect. Some blowers will use the benderback technique. One end is terminated and the tube is then turned to a ball of glass. A hole is (popped) 90 degrees from the termination to then switch the axis. Next, the other end is terminated and you have a switch ball. This can take roughly 2-3 hours to make 10-15 switch balls, or approximately 10-15 minutes per switch ball. The cleaner the ball the longer it takes to make.



Potential hazards also exist any time you work with compressed gasses. Carefully follow any manufacturer’s instructions that come with your regulators or gas tanks and check with your suppliers for safe operating procedures.

Never move oxygen tanks without their protective cap in place. If the tank falls over, the valve stem can be sheared off by impacting against a table or other object. The pressure inside the tank may then be high enough to send the cylinder flying like a rocket, injuring you and damaging your building.

Oxygen tanks should be either laid on their side and secured to prevent rolling, or chained securely to a wall so they don’t fall over. Note also that oxygen regulators, hoses and fittings should never come into contact with grease or oil, which can ignite spontaneously in the presence of pure oxygen.

Be sure to install check valves and flashback regulators on your fuel, gas and oxygen regulators to prevent backwards flow of gasses-a major hazard in the event of a fire or torch malfunction.

Make sure that your torch is secured to the work surface so that it doesn’t move if a hose is yanked. Keep all flammable and combustible materials well away from your torch.

At the end of each work/play day, shut off your oxygen and gas tanks and bleed the pressure out of the lines by opening your torch valves.


Thermal Coefficient of Expansion

Also: COE, LCE, α (alpha); The relative amount by which a material will expand per degree when heated. The smaller the COE, the more resistant the glass is to thermal shock. Expressed as an exponent, Borosilicate’s COE is ~3×10⁻⁶ K⁻¹ at 20°C


Thermal Shock

The strain created by abrupt heating or cooling.



An instrument for measuring and indicating temperature.


Titanium Pen

A piece of metal ground or filed to a point.

Titanium Pen by a blower – This used to sign a blowers art. The glass must be wet to write with the piece of metal. It leaves a mirror like signature when used properly.


Twisty Cane

A piece of rod or cane that has been twisted to give a candy cane effect.

Twisty Cane by a blower – There are a few ways to make a twisty cane in glass blowing. One method is to take a clear rod, maybe 10 or 8 mm. Then take some colored rods and trip the clear rod. Heat it up allowing the colors to melt to one piece and get it like a foot ball. Then pull it and twist it to a cane or stringer. A second method is to take the colored rods and bundle them how you wish the colors to go. Then melt to a 10mm or lager rod and melt into a foot ball again. Then pull and twist into a cane or stringer.


Uranium Glass

Uranium glass contains Uranium, and emits low levels of radiation. Like any borosilicate color, it should be handled with proper safety procedures, including wearing a full tight fitting style, NIOSH certified respirator, with a P100 rating on the cartridge, any time you are creating, or working around glass dust. Like dust from any borosilicate color, you do not want to inhale or ingest any dust. In addition, we recommend you do additional research, in addition to the resources referenced below, to learn about long term low level radiation exposure, especially in cases where this glass will be in close proximity to a person, like wearing a pendant. More information on uranium glass can be found here:


Buckley et al. Environmental Assessment of Consumer Products Containing Radioactive Material. Nuclear Regulatory Commission. NUREG/CR-1775. 1980.

Landa, E. and Councell, T. Leaching of Uranium from Glass and Ceramic Foodware and Decorative Items. Health Physics 63 (3): 343-348; 1992.

Nuclear Regulatory Commission.  Systematic Radiological Assessment of Exemptions for Source and Byproduct Materials. NUREG 1717. June 2001.


UV Reactive Glass

Glass that when UV light is on it changes. This glass can be one color outside or under florescent lights, but when you put it in the dark and put pure UV light on it, WOW it glows way different than it did in the light. Below are what is kinda on the market now. The market is always growing with new colors coming out near weekly. We have found the best nano-meter wavelength is from 365 to 380.

Green – Many people call this illuminati as North Star was one of the first to bring it to the borosilicate art glass world. This glass has radioactive uranium dioxide in it. This glass is light green or yellowish in plain light, but POPS bright green under UV light.

Blue – The first we seen bring this to the market was Trautman Art Glass called Blu-V. These are trade secrets from what we know of what goes into these. But we think maybe it is fluorite as it glows blue/purple.

Pink – Lucy was the first we seen on the market by Northstar. Again, we do not know what its made with but we think it is Calcite.



A fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the informal concept of “thickness”; for example, honey has a much higher viscosity than water.

Viscosity is a property of the fluid which opposes the relative motion between the two surfaces of the fluid that are moving at different velocities. In simple terms, viscosity means friction between the molecules of fluid. When the fluid is forced through a tube, the particles which compose the fluid generally move more quickly near the tube’s axis and more slowly near its walls; therefore some stress(such as a pressure difference between the two ends of the tube) is needed to overcome the friction between particle layers to keep the fluid moving. For a given velocity pattern, the stress required is proportional to the fluid’s viscosity.

Viscosity by a blower – This how the glass gets liquid. Clear has no other elements making it the thinnest or runniest of glass in the boro world. The more saturated a color is the higher the viscosity is. This becomes very apparent when a blower makes lined tube work with a high and low viscosity color. The low viscosity colors will kinda condense and pull together. The blower must learn to work this properly such as if it was half black and half white, the blower may do 8 lines black and 10 lines white. When worked they may end up looking like they had the same amount of lines for the color.


Wet Room

This is a dedicated room where a blower will do cold work that uses water to lubricate as it is cut. Many times you will find a lapping wheel, diamond saw, maybe a drill press with a diamond bit even.



This is a piece of glass that a blower places in another piece of glass. This make it look like there is a window in the glass. The window can be a switch ball, clear glass, bubble trap or any piece of glass the blower wishes to put inside the glass. Usually the blower must switch the axis of the glass so that the piece of glass he/she puts into the glass is on the side to make a window effect. This is a higher skill set for a blower.


Wrap and Rake

One of the more basic yet when done right can be just amazing!  This technique gives the glass like a scallop effect of dragging effect.

Wrap – This part of the technique is what will give the underlying pasterns and colors.  You will take a warm piece of glass, the hotter the better so the colored glass will stick to it.  You can also fume the glass and wrap with clear or any color for that mater.  To wrap the glass you must develop a technique of spinning the hot glass while taking a stringer off the clear or colored rod of glass.  The faster you spin the thinner the stringer lines, the slower the thicker the stringer lines will be.  Once you have it wrapped I like to heat up the color or clear stringers that wrap the glass and paddle them slightly to the glass to make sure they are sticking good.


Rake – This is the second part of the technique that will give the wrap the near effect. Mostly I use a clear 5mm rod for this, but you can use nearly any color, while transparents tend to give the best effect. To start the rake process you will pre heat the glass rod you will be using to rake. Then heat up a line on the glass you wrapped. Once you have the line heated you will run the flame at an angle so that you just slightly hit the wrapped glass while pulling the clear through the wrapped glass. This is what make the pulling effect as you will pull the clear through the spun color. Repeat this over and over. You can go close next the the prior rake, or you can go further away. You can even rake towards you, then rake away. There are a ton of things you can do with this technique and never seems to get old.


Wig Wag

This is when a blower twists lined color back and forth making a say wig wag pattern, hence the name. There are a lot of ways to make this happen, but the ultimate goal is to get that back and forth pattern. One great technique is the bender back way.


  1. Wikipedia

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