Very thin, small pieces of broken glass are called confetti or shards. Confetti is used as a design component by kilnforming and hot glass artists.
One common way to create confetti is for a glass blower to blow an enormous bubble of glass. Because the glass is so thin, it cools (and anneals) almost instantly. The “frozen” bubble is then shattered.
The glass used to make confetti is typically formulated with more coloring oxides so that even when paper thin the color is appropriately dense. The result is that the glass used for confetti is less compatible than compatible sheet glass. For this reason, confetti should not be layered thickly.
Kilnforming artists can also make their own confetti using a drop ring placed as high as possible above the kiln floor and letting a single sheet of glass stretch thinly as it is slowly heated. Opalescent confetti can also be made by firing large powder wafers and breaking them into pieces.