How to Use the Original Colors

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The Original Glass Colors product line are easy to use, beautiful and inexpensive! These colors were formulated primarily for use on glass but they can be used on ceramic or porcelain and over fired glazes. We use single or double strength window glass available from a hardware or building supply store. When sagging a piece, 12" or larger, we recommend using double strength glass or using two pieces of single strength. Clear, colored or textured stained glass from a stained glass supplier will also work well. Colors can be brushed, sponged, airbrushed or applied with the outline bottle. When spraying, proper equipment, including a mask is necessary. When brushing, select a soft brush such as one from the 250 series. Thin the colors to the consistency of milk and "puddle" them on. To cover a large area (background, etc.), apply the thinned color with an eyedropper and use a brush to bring color up to outlines. All colors dry slowly to allow brush marks to level out and one coat is all that is necessary. Colors will tend to settle somewhat in the jar and will have to be stirred and shaken before and during use. If the color is too thick and the brush marks do not smooth out, add a few drops of water. You want the colors to flatten out to a smooth application. If Glass Colors dry out in the jar, add enough water to return them to a painting consistency.If you wish to shade these colors, apply 2 colors side by side and while still wet, "squiggle" them together using a fine blush, or apply the base color and when dry, Shade using the shading color on a square shader brush.Outline Black and Outline White can be used for outlining to achieve the leaded glass look. Place pattern underneath well cleaned glass and trace on the outline of your pattern, using the Outline Black with a 10/0 brush or the Outliner bottle (squeeze bottle with the metal tip). When outline is dry, you will be able to apply color to the different sections of your pattern, and the outline well not bleed or smear. If color is accidentally applied over the outline, immediately use your finger to push it back across the line. Many ready to use shapes and styles of glass slumping molds are available. Be sure to place your glass painted side up when using a sagger/ draper.  The maturing temperature of the colors is hot enough to cause the glass to conform to the shape of the mold being used, so you will be decorating and forming the glass at the same time.

Always scrub your glass on both sides using powdered cleanser (Comet), rinse well and dry with a paper towel. This will remove fingerprints, dust or oils. After cleaning, handle glass by the edges only, as any contamination will show after the piece is fired. Another option is working on a surface that has been etched. Colors will adhere to the etched surface with no "beading" or crawling. This etched surface will become shiny and clear when the colors are fired to maturity.

These original colors are not food safe, but they can be used for food containers if the color is fired on the outside of the shape. Fire these pieces on a drape mold with the painted side up, this leaves the inside free of color

Firing Instructions

Electronic kilns usually offer two options for firing. When working with glass, you can program them to fire to a specific cone at a medium speed or you can override this and use the ramp feature.

If you find programming your kiln for cone firing does not give you satisfactory results with glass, use the ramp mode. (Check your manual for complete details on how to use this feature.) This will allow you to program to a certain temperature and "ramp" the rate up by so many degrees per hour. I would suggest that when firing single layer glass, you use 400F increase per hour to maturity with no hold (soak) time at the end of the firing cycle.

If you are fuse firing 2 layers and wish to have the small bubbles in the color, set the rate of increase to 300 degrees per hour to 1480F or to cone 016. *see below

We suggest the following schedule when fusing two or more layers of float glass or when firing a fused piece for the second time. This is a very slow schedule and will enable gasses to escape to prevent bubbles.

Firing segment

  1. 300F per hour hold at 500F for 10 minutes
  2. 300F per hour hold at 900F for 10 minutes
  3. 9999 per hour to 1480F
  4. Cool and hold at 900F for 5 minutes
  5. Cool at 250º per hour and hold again at 800F for 5 minutes
  6. Off and allow to cool naturally

The above is offered as a suggestion, a starting point, and you may need to adjust for your kiln. Float glass will mature at 1450F in some kilns and need as much as 1550F in other kilns.

Glass Colors have a wide firing range, 1400F to 1800F. The upper end of this range is much hotter than glass can withstand, it will melt into a puddle!

As you know firing temperature is governed by a combination of time and temperature and all kilns are different. Firing any material, especially glass, is an art. Age of the kiln and placement in kiln will effect the results. Top shelf is usually hotter than lower shelves.

If you are new to firing glass, we suggest that you experiment with undecorated glass and the sagger you intend to use before firing a decorated piece.