We are all a bit guilty of casually using the term Cast Glass when describing Slumped Glass. So, why the misnomer? My guess is that architects and other design professionals prefer the sound of cast verses the less romantic term slumped. But the fact is that these are two very different processes:
1) Glass casting is the process in which glass objects are cast by directing molten glass (which is hot ladled from the furnace at temperatures of about 2,192°F to allow it to freely pour) into a mold where it solidifies.
2) Slumped Glass, on the other hand, is the process of bending or slumping glass over or onto a mold. By heating to approximately 1,300‒1,400°F, the initially flat glass will take the form and texture of the mold beneath it. At times, this may take on the appearance of Cast Glass.
Regardless, as long as the design industry prefers the term Cast Glass over Slumped, we will all abide.