The glassblower then begins inflating the gather of glass with a few short puffs designed to open up a cavity and create an elastic interior skin similar to the one that has formed on the exterior surface. Next, he quickly inflates the gathered glass to the desired size. Sometimes for more standardized factory pieces, the glassblower blows the glass into a mold (seen here) to ensure that every piece will be roughly the same shape and size. For an art piece, however, he might choose to do “freeblowing” without a mold, which will imbue a piece with its own personal quirks.