Our Artist in Residence answers your questions
asks: "Is there any way to use regular card stock instead of watercolor paper for watercolor projects?"
A: Cardstock is usually intended for printing applications where ink needs to dry instantly... I've found that water soaks into the surface too quickly to do any extended water blending or wet-into-wet techniques. It can even leave raised spots on the cardstock after it's dry. Watercolor paper usually has at least some cotton content (I prefer 100% cotton paper). It also is prepared with sizing, a coating of gelatin or starch that helps the paper absorb water more slowly. There is a surface prep medium called watercolor ground that can be used to create a watercolor-ready surface on papers, or even fabrics, wood, plaster, metal, plastic, and glass. It's spread or brushed onto the surface of whatever you want to paint.