Looking for reusable stencil material.

I am looking for stencil material that is reusable and I can cut in my laser. I am assuming Mylar is the best choice but I am unsure on thickness.

I can find it online but it is by the sheet not in bulk and fairly expensive. I'd like to find something in rolls or maybe a hundred pack of 81/2x11 sheets.

(.-.)

Looking for reusable stencil material.