TALAS offers a wide variety of bookbinding board, and binders
Lineco Acid-Free Binder's Board
BBTO 20 Pcs Book Board, 80 Pt 0.086'' Thick Binders Board
Binding boards - Binder's Board - Lutrex
Book Binders Board Acid Free 14.5 X 20.5 Pk/4 99295612517
Bookbinding Tools & Materials - beginner friendly
Bookbinding Kit Complete Cased in Hardcover Journal Bookbinding
Davey Board — Colophon Book Arts Supply
Custom Print Unique Educational Preschool Activity Learning Binder
Acid-Free Binder's Board .067 15x20.5 4 Sheet Pack