4 ply bristol board is great for projects, signs and art projects. 100 pack size is great for larger projects or multiple classrooms at an economical price. Thicker than 4 ply bristol board which makes it sturdier for all projects and other uses. Poster board is available in 13 bright colours - canary, pink, blue, white, red, green, brown, kelly green, orange, royal blue, black, magenta and assorted. Sheet size is 57cm x 72cm (221⁄2" x 281⁄2"). 100/pkg.