How to make a glass pumpkinAlthough there are different ways of working with glass, here's one way to make a pumpkin, according to the Bay Area Glass Institute:
An artist uses a blowpipe to gather melted glass out of a furnace, then rolls it in colorful crushed glass called "frit."
The glass is then put into another furnace, called a "glory hole," to heat it again and melt the color into it. (Throughout the process, the glass must be continually reheated to keep it malleable.)
An artist blows into the pipe, making the glass into a bubble. The bubble is shaped with a pad of wet newspaper, and then blown into a mold to form the pumpkin's ridges.
The artist keeps blowing into and working on the bubble, adding another piece of glass for a stem.
Finally, the pumpkin is broken off the pipe and its bottom flattened with a torch. Since it will crack if it cools too quickly, it's placed in an annealing oven to cool slowly overnight.