Pacon® White Poster Board, 11" x 14", 5 Sheets Per Pack, 12 Packs | Michaels
Amazon.com : Trifold Poster Board 36" x 48" White Presentation Board Science Fair Display Boards - for School, Fun Projects and Business Presentations - by Emraw : Office Products
ARTSKILLS Heavyweight White Poster Board, 22" x 28" - Walmart.ca
Find 22" x 28" White Poster Board, 10ct. | Michaels