I went to Arch last evening to pick up some 100% cotton paper. Cotton paper takes letterpress impressions best, but it is expensive. It is about $5 for a poster-sized sheet. Anyway, Arch is the best store ever. If you visit San Francisco don’t leave without stopping by. They have every art supply you can think of and their gift section is one of the best in the city. I also love that they are locally owned, there is a cozy and friendly feeling inside their warehouse-sized shop. Find them in Potrero Hill in a giant copper painted building.