Pina Zangaro Tera 11x17 Landscape Screwpost Portfolio Cover OnlyMade of pressed hardboard, these screwpost covers have a slightly retro look, yet are still contemporary and highly functional. Available in four standard formats, these books are compatible with all major brands of sheet protectors, mounting sheets and adhesive hinge strips. Nylon jackets (sold separately) are available for all formats to protect your portfolio from light, dust and scratches. Expand the portfolio’s capacity with standard screwpost extensions (sold separately). Lies flat when open.