30% Shade Cloth - Small Piece (Petaluma)

I am looking for a small piece of 30% shade cloth that is minimum 2X2 ft (bigger is fine). It is for an indoor science project I am doing at school. It must be 30% or 40% shade. 50%+ will not work for my project. Any color. Petaluma pickup location. (I'm on a bike). Thank you :-)