Baumfolder Flexifold: 8-Page (from 2003 thru 2005) - Manual (Page 28)

TP10432 PAGE 28
17.0 BASIC THEORY OF BUCKLE
FOLDING
If a sheet of paper is laid on a flat surface and driven into
a stationary object, a buckle or series of buckles will form
along the surface of the sheet.
If the sheet of paper is pushed into a narrow channel
before butting up against the stationary object, the buckles that
form within the channel will be of a much smaller size than
free-forming buckles. At the end of the channel, however,
larger buckles will again start to form.