A
pastry bag (or
piping bag in the
Commonwealth) is an often
cone- or triangular-shaped,
hand-held bag made from
cloth,
paper, or
plastic that is used to
pipe semi-solid
foods by pressing them through a narrow opening at one end, for many purposes including
cake decoration. It is filled through a wider opening at the opposite end, rolled or twisted closed, and then squeezed to
extrude its contents.