20 pieces of book board.
Each piece is 8.5" x 5.5" (about 215mm x 140mm).
This is an archival quality, composite grey cardboard specifically designed for bookbinding.
Acid free and lignin free.
Thickness is 90 pt.
You will get 20 pieces, each 8.5" x 5.5"
Boards will be a mixture of long and short grain.