I made a bunch of holiday cards yesterday using my new favorite technique: using the Silhouette digital paper cutter to cut vinyl stickers as paint masks on watercolor paper. The results are extremely crip. There is absolutely zero bleeding, even if you use a ton of water. It really surprised me how well the vinyl keeps out the watercolor.
I made an Instructable to follow if you want to make one yourself.
Here is the process (photos below):
1. Create your design in the Silhouette design app. I used a combination of designs I had and one I bought from the Silhouette store.
2. Cut them out on adhesive-backed black vinyl.
3. Use transfer paper to transfer the vinyl sticker to the watercolor paper.
4. Watercolor paint a bit over the stencil.
5. Remove the vinyl stencil.