At fusing temperatures, the
At fusing temperatures, the glass will naturally flow until it is about 1/4″ (6 mm) thick. That’s two layers of typical glass. If you stack three layers, it will flow. If you put in one lone layer, it will draw up.
This is caused by surface tension in the molten glass. It is the same force that causes water to bead up on your kitchen counter. When you put more water on the counter the drops don’t get taller – just wider.
Helios Kiln Glass Studio