cardboard
A board 0.006 inch or more in thickness. It is
stiffer than paper. Although the generic term
"board" is used in lieu of the term "cardboard" in
bookbinding parlance, the covers of many
pamphlets, brochures, etc., as well as the card
used to line prints, posters, etc., and also used
in FILLING IN (1)
, are of a thickness that would fit them into the
definition of cardboard. (17 , 234 , 264 )