One common pattern
for an envelope is shown below, but other shapes also
To cover a sheet of paper with many copies
of the same shape so that there are no holes or overlaps,
the copies have to fit together.
A rhombus, with four sides of equal length, as pictured
below in red will
To create tabs for gluing an envelope together,
many manufacturers cut notches in the edges of each pattern,
as shown in the following diagram. This is the only waste
paper in the design. The pattern is then folded in the
directions indicated by the arrows.
Other patterns also are used, such as the
one shown below, but these may waste slightly more paper.