Hilarie Cornwell told me about pergamenata, a cellulose-based parchment substitute. I love it...tough like real animal skin parchment, but not greasy. It comes very smooth and I usually rub it with a gum eraser before drawing. It does like to curl up once painted, though. I once finished a piece late at night, went to bed, and woke up to find it had disappeared. Turns out it had rolled up overnight and rolled right off the desk.
It looks like a lot of people here work on paper, which is exciting to learn!