Art Supplies

Hi everyone, I'm visiting Sri Lanka on an extended stay with a friend in Galle. I'm a painter by trade, and just received a commission to do a series of small paintings. I thought I'd get to work on them here, as I am travelling with my paints and brushes, but I can't find any art supply stores to buy canvases. Is there one in Colombo? I also work with polycarbonate sheets. The hollow plastic that is often used in the USA for lightweight signs. I haven't seen it in use here, has anyone else noticed it around?