Bullseye Glass Tech Notes & Tips

Bullseye Kiln-glass Education Online

Top-rate instruction in the art and craft of kiln-glass in the comfort your own home or studio.

Bulleye TechNotes:

  1. Knowing Your Kiln – Bullseye TechNotes #1 (May 2011)
  2. Knowing Your Kiln – TechNotes #1 (May 2007)
  3. The Vitrigraph Kiln – Bullseye TechNotes #2 (Aug 2009)
  4. Compatibility of Glasses – Bullseye TechNotes #3 (2010)
  5. Compatibility of Glasses – TechNotes #3 (Jan 2013)
  6. Heat and Glass – Bullseye TechNotes #4 (June 2012)
  7. Volume & Bubble Control – Bullseye TechNotes #5 (Oct 2010)
  8. Preparing The Kiln Shelf For A Large Kiln – Bullseye TechNotes #6 (Oct 2008)
  9. Monitoring Kiln Temperatures for Successful Annealing – Bullseye TechNotes #7 (Aug 2009)

Bullseye Glass & Quick Tips:

  1. Glass Tips: Opalescents (2011)
  2. Glass Tips: Transparents (2011)
  3. Torch Tips: Opalescents & Transparents
  4. Quick Tip: Frit Balls  (Oct 2012)
  5. Quick Tip: Use Bullseye Clear Powder to Fix Surface Flaws (Jan 2010)
  6. Quick Tip: A Riot of Effects (Feb 2012)
  7. Quick Tip: River Rock Reaction (April 2012)
  8. Quick Tip: Glimmering, Shimmering Irids  (April 2012)
  9. Quick Tip: Multitasking Molds (July 2012)
  10. Quick Tip: Inky Blue Brush Strokes  (Sept 2012)
  11. Quick Tip: Holiday Punch (Dec 2012)
  12. Quick Tip: Powder Power (Jan 2013)
  13. Quick Tip: Iridescent Squares (April 2013)
  14. Quick Tip: Get the Look with Stripes and Dots (July 2013)
  15. Quick Tip: Opaline Ring (Oct 2013)
  16. Quick Tip: Fresh Color (Feb 2014)
  17. Quick Tip: Fine Line Stringers (April 2014)

Bullseye Mold Tips

  1. Pyramid Casting Mold #8948 (May 2010)
  2. Cone Bowl Molds (August 2013)
  3. Big Bowl (August 2013)
  4. Deep Form Three-Step Process (August 2013)

Bullseye Tipsheets

  1. Kilncarving – TipSheet #1 (Feb 2011)
  2. Working With Accessory Glasses – TipSheet #2 (2001)
  3. Working Deep – TipSheet #3 (Nov 2012)
  4. Designing Your Own Art Glass – TipSheet#4 (2012)
  5. Designing Your Own Art Glass – TipSheet#4 (Jan 2013)
  6. Bullseye Box Casting – TipSheet #5 (2009)
  7. Bullseye Box Casting – TipSheet #5 (June 2013)
  8. The Amazing Roll-up – TipSheet #6 (2005)
  9. The Amazing Roll-up – TipSheet #6 (Dec 2012)
  10. Platemaking Tips – TipSheet #7 (Nov 2012)
  11. Basic Lost Wax Kilncasting – TipSheet #8 (Sept 2009)

Bullseye Studio Tips:

  1. Annealing Thick Slabs (June 2009)
  2. Fahrenheit/Celsius Converters
  3. Glass Cleaning Basics (Dec 2007)
  4. 12 Ways to Improve Your Glass Cutting (Oct 2008)
  5. 12 Ways to Improve Your Glass Cutting (May 2012)
  6. Bullseye Blank Firing Schedule Project Sheets (July 2012)
  7. Recommended Annealing Cycle for Bullseye Glass
  8. Safety in The Kiln-Glass Studio (Sept 2010)

Bullseye Product Use Ideas:

  1. Bullseye Colorcues Intro (2005)
  2. Bullseye Color Cues: Brights (2005)
  3. Bullseye Color Cues: Dusk (2005)
  4. Bullseye Color Cues: Spring Lake (2005)
  5. Bullseye Color Cues: Pink Martini (2005)
  6. Frit Tinting (Aug 2007)
  7. Bullseye Brainstorm: Texture & Irids (Dec 2008)
  8. Get A Reaction: Recommended Copper Bearing Glasses (June 2009)
  9. What to Expect From Opaline Striker Frit (Nov 2010)
  10. Tips for Using Bullseye Slumping Molds (Dec 2010)
  11. Bullseye Shelf Primer Instructions (Jan 2011)
  12. Special Effects: Steel Blue Opalescent (May 2011)
  13. Reaction Potential for Bullseye Glass, Rods & Stringers (Aug 2012)
  14. Get A Reaction: Bullseye Reactive Glasses (Sept 2012)
  15. Bullseye ThinFire Shelf Paper (May 2013)
  16. Reactive Potential of Bullseye Glass, Rods & Stringer (March 2014)

Bullseye Glass Make-It Projects:

  1. Make It: Dilution Solution (Feb 2011)
  2. Make It: Inline Plate (July 2013)
  3. Make It: Linear Reaction (Feb 2011)
  4. Make It: Opaline Striker Sushi Set (Feb 2011)
  5. Make It: Tint Tones Plate (Feb 2011)

What To Expect From Bullseye Glass

Bullseye is widely recognized for its sophisticated palette of harmonious colors. Most styles are available in two thicknesses: double-rolled 3 mm sheets and Thin 2 mm sheets. Due to the handcrafted nature of the product, all sheets have at least one rolled edge.

what to expect size diagram

Dimensions are approximate.

Color Variation

While Bullseye strives for consistent colors, our glass is a handmade product and colors may vary slightly between production runs (and from images in the catalog). Some colors may change slightly upon repeated firing or with extensive heatwork. We recommend that you test samples of glass using the same firing cycles and processes to be used in finished pieces.

Colors That Strike

In order to provide the largest and most interesting palette of colors to kiln and torch workers, Bullseye produces some glasses that appear pale or colorless in the cold form but which “strike” or mature to target color upon firing. Catalog illustrations indicate which styles differ in color from cold form to struck form. Keep in mind that struck color may vary depending on temperature, atmosphere and amount of heatwork. For example, heating Ruby Red Tint Striker (001824-0030-F) too rapidly during the initial stages of a firing cycle can prevent the glass from striking correctly, resulting in a blue-brown cast (sapphirine effect) instead of a true ruby red color.


Unstruck colors on the left. Struck (mature) colors on the right.


Bullseye glasses are well known for reliable compatibility. But understanding the conditions of our factory testing is important, especially if you are firing glass under unusual or extreme conditions.

At Bullseye, glasses known to be fairly stable are tested by firing to a top temperature of 1500°F (815°C) and soaking for 15 minutes before annealing. Once cooled, these tests are viewed for stress through polarized light and graded accordingly. Other glasses known to be less stable are fired three times with this cycle to insure good performance under typical multiple fusing and slumping conditions, such as those used in making a simple plate.

If you are using a heat process that involves an extra-high temperature or an unusually long firing time, we recommend that you test the glass again, under the conditions specific to your project. For instance, imagine that you want to include some flameworked elements in a kilnformed project. Consider that flameworking takes glass to temperatures exceeding factory compatibility tests; also, the compatibility of some glasses is more sensitive than others to extensive work in the flame. Therefore, it will be important not to overwork your glass during flameworking and to test the flameworked components for compatibility using the full range of kilnforming processes planned for the finished project.

Some processes that may not immediately appear to exceed the parameters of the test for compatibility actually do. Holding some glasses for long times at temperatures around 1400°F (760°C), which is in the devitrification range, can cause the glass to change dramatically.

Many artists (Klaus Moje, for example) are able to push Bullseye glass to high temperatures for long times with exceptionally good results, but their success is insured by their own testing before making large or complex pieces. Testing is a wise practice with whatever glass you use. No manufacturer can guarantee glass to perform as expected under all imaginable working conditions.

Revised December, 2010.


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