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
Elmer's Tri-Fold Corrugated Display Board, 28" x 40", White - Walmart.com
Pen+Gear White Tri-Fold Cardboard Project Display Board, 28" x 40" - Walmart.com
Amazon.com : Jutieuo 4 Pack Trifold Poster Board Tri Fold Display Presentation Board for School, Fun Projects, Foldable White Poster Boards with 2 Rolls of Double Sides Adhesive Tape (16 x 24 Inch) : Office Products