To avoid pulling in of the rim (lengthwise) choose a very low slumping temperature with a long soak.
Recommended Firing Chart
Please Read: This firing recommendation has been calculated for use with Bullseye Glass of average viscosity with an even thickness of 4 - 6 mm. The chart shown below is also based on the assumption that you are using a top fired kiln, e.g. Paragon GL22, GL24, BVD Flat bed kilns etc. If you are using a side firing kiln you must allow more time in the first ramp.
Please note that all our moulds are hand-made and therefore the dimensions may vary from those shown.