Quick Tip: Circles from Squares | Kilnforming

Quick Tip: Circles from Squares


The Stack

Top (6 mm): A “lensing” layer of Clear. This layer will stretch considerably.

Middle (3-4 mm): This “design” layer will stretch and be visible through the top layer. Use part sheets or pieces of 3 mm sheet glass.

Bottom (6 mm): Typically not visible from the front. This layer will stretch the least.


  • 6 mm Tekta Clear is a natural for this project. It’s more efficient, with fewer pieces to cut, clean and assemble! Measure and score a grid of 0.75" squares, then run them using the Rule of Halves. Two layers of 3mm will also work.
  • A dab of GlasTac Gel will keep the stack together before firing.
  • The stacks flow out to about 1.25" (32 mm) in diameter, so give them room.
  • For the cleanest release, we recommend firing on ThinFire

Cabochon Firing Schedule

Rate Temperature Hold
400°F (222°C) 1225°F (662°C) :30
600°F (333°C) 1525°F (829°C) :30
AFAP 900°F (482°C) 1:00
100°F (56°C) 700°F (371°C) :00
AFAP 70°F (21°C) :00

Note: This heatwork goes beyond what the glass is tested for. Some styles may opalize and/or shift in compatibility. Test before making multiples.

Some Design Layer Possibilities

Cabochon possibilities

Revised February 2, 2017.


Downloadable PDF
Quick Tip Circles from Squares