1. On one side of a coffee filter, draw whatever design you'd like in washable markers.
2. Wetting your fingers, flick some water onto the filter. You'll watch the colors spread across the filter. Don't use too much or this could turn into a soggy mess! I cut the kids off after a few sprinkles of water from the bowl.
3. Let the filters dry and then cut them into whatever shapes you like. I used a paper punch to make different sized pieces and then taped those onto the window for a stained glass effect. The possibilities are endless. Have fun!