Firing Schedules & Color Guides

Full Fuse Mosaic Sheet- 1 Layer  600- 1510- 10 Full- 1050 – 10 * Full- 850 – 10 *  ** 100- 100 – off   Full Fuse Mosaic On Cut Outs (Glassy Cut Shapes) 600- 1510- 10 Full- 1050- 10* Full- 850- 10*  ** 100 – 100 – off *hold longer for thicker projects ** come down slower for thicker projects   Slump Mosaic Pieces 300 – 1300 – 10 Full- 1050 – 30*a Full- 850- 20*b&c 100- 100- off *a- 30 minutes or longer depending on the size & thickness of the mold you’re using. Mosaic pieces that are stacked 3 or more in height should be slumped very slowly or your project will split. *b- Slower than the full 9999 depending on the size & thickness. We will slow this down as love as 50 degrees per hour *c- Hold here longer also if it’s a thicker piece or on a metal mold.   NOTE: Metal molds hold their temp longer than glass so you could shock you glass and break it.

 

1. *600 – 1425 – 11
2. Full – 1050 – 10*
3. *Full – 850 – 10

  Same info as above for ramping up or annealing down. Temps change with the size, thickness, and multi-layers of your project. Multi-layers include mosaic too.

 

1. *300 – 1300 – 10
2. *Full – 1050 – 10
3. *Full – 850 – 10
4. 100 – 100 – OFF

  Again, be careful with ramping your temp too high in the start or dropping your temps too fast. If you are slumping on or over metal- slow it way down to avoid thermal shock from metal retaining its heat longer than glass.   NOTE: Metal molds hold their temp longer than glass which can shock your glass and break it.

Slow – 1300 – 5 Ramp down slowly *Remember- any texture or embossing will flatten out at 1300. A trade trick is to grind your piece & add a swab of Liquid Luster from Olympic Glass in Seattle.  

Do not steam plaster of paris molds. Both types of molds will need kiln-wash prior to casting glass!

1. 9999 – 190 – 3 hrs
2. 250 – 1500 – off

*Will throw a good amount of steam so your kiln should have stainless steel parts/ hangers or it will rust!

SMALL BOTTLES:

300 – 1100 – 5

300 – 1300 – 10

500 – 1425 – 5

9999 – 1000 – 30

100 – 200 – off

*LARGE BOTTLES:

300 – 1100 – 30

300 – 1300 – 60

500 – 1425 – 5

9999 – 1000 – 60

50 – 800 – 60

100 – 200 – off

*Large bottles should have temps that are held out longer to avoid thermal shock. This is due to the base laying down & creating a thick area compared to the rest of the bottle.

Ramp up at a normal rate for project to 1300 – Hold for atleast 15 minutes (test) Then ramp up normally to fusing temp.

In a mold: 1. 500 – (1425 to 1450) – 10 2. Full – 1050 – 10* 3. 200 – 100 – off Out of the mold: use regular tack or full fuse, depending on the final desired look

A simple guide to choosing, layering, and combining float glass colors

First things first: our colors don’t behave like paint

Float glass colors don’t mix the way a traditional color wheel does. When colors overlap, they layer — they don’t blend. That means:

• Red + blue ≠ purple
• Blue + yellow ≠ green
• Mixing across color families often creates muddy browns or grays

This isn’t a mistake — it’s just how glass works.

Color “Houses” (Your safest starting point)

When choosing colors, we recommend staying within one color family. Cool Colors (work beautifully together)

• Blues
• Greens
• Purples
• Pinks

Warm Colors (work beautifully together)

• Reds
• Oranges
• Yellows

Neutrals (their own special category)

• Whites
• Blacks
• Grays

Neutrals pair best with other neutrals and cool colors, but they don’t always play nicely with warm colors. If you choose to mix across color houses — go for it! Just know that results may be unpredictable (and sometimes surprisingly cool).

Layering Rule: Light → Dark

When layering glass powders or frit, order matters. Unlike paint, glass doesn’t mix together; it stacks. Because of this, the sequence in which you apply color has a major impact on the final result. The golden rule is simple: Start with your lightest color and build up to your darkest. This matters because dark glass is extremely strong. If a dark color is placed underneath a lighter one, it can visually overpower it, causing the lighter color to disappear or become muddy. This often feels surprising to beginners, but it’s simply how light behaves in glass. When light or transparent colors are placed first, they can still glow through darker layers added on top. This allows color relationships to stay visible and intentional. In practice, this usually means beginning with light, transparent colors, adding medium tones next, and saving darker or more saturated colors for last. This approach gives each layer a chance to be seen rather than absorbed. If you reverse this order, lighter colors may seem to vanish entirely because the darker glass beneath is blocking light from reaching them.

Combining Transparent and Opaque Colors

When working with both transparent and opaque colors, layering becomes even more important. Transparent colors allow light to pass through, while opaque colors block it. Because of this, transparent colors should generally be applied first, with opaque colors layered on top. In most cases, opaque colors work best as the final layer. This creates clear visual separation between colors, adds contrast, and allows transparent layers beneath to contribute depth without being lost.

How light affects your colors

One of the most important things to understand about float glass is how it interacts with light. Color in glass isn’t just about hue — it’s about whether light can pass through the material or not.

This is where transparent and opaque colors behave very differently.

Transparent Colors

Transparent glass allows light to pass through it. When layered, transparent colors don’t cover what’s underneath — they build on it.

This means:

• Underlying layers remain visible
• Colors stack and interact visually
• Pieces feel lighter, deeper, and more dimensional

Transparent colors are great for glowing effects, subtle gradients, and layered designs where you want depth.

Think of transparent glass like layers of colored light.

Opaque Colors

Opaque glass blocks light. Once an opaque color is applied, it becomes the visual stopping point — whatever is underneath it is largely hidden.

This means:

• Colors appear bold and solid
• Underlying layers may disappear
• Opaque colors visually sit “on top”

Opaque colors are powerful and beautiful, but they are dominant — even a small amount can overpower lighter or transparent layers.