They are sturdy, clear plastic.

plus I liked the clear plastic for its invisibility.

Acrylic is good quality, not cheap plastic

Plus they're a bit more inconspicuous with the clear plastic.

sturdy plastic

Crystal clear plastic that looks nice.

Acrylic is good quality, not cheap plastic

Sturdy, heavier plastic than others, and perfect for the small recipe booklets to be organized into for the bookcase