Where to find black acrylic locally

[tonymission]

Before I order online and pay $30+ shipping and $19 for a single cut, does anyone know where I can find some black acrylic locally? Doesn't need to be thick, just need one or two 2x4' pieces to hang off my horizontal light mount to reduce spill on the frag tank. I like to take naps down there sometimes and the new fixture gives me a headache. Plus I can probably increase PAR a bit too.