If you aren't a fan of origami before you enter Paper Tree, you will be after, especially if you run into Linda Mihara, international origami artist. She'll share more about her work when she's not helping customers in search of origami, papers, books and other art supplies. A small area displays the creations of Mihara as well as Robert Lang, Brian Chan and Bernie Peyton, whose artistry is a complex mix of geometry and genius. It's a rich experience, and browsing is free. 1743 Buchanan Mall; (415) 921-7100, http://www.paper-tree.com.