Oil and water droplet painting is the result of mixing cooking oil and colored water to create a beautiful, slightly marbleized effect. You can find such paper at a craft or stationary store, or you can invite your kids to help you make some of your own.
Supplies needed are a shallow pan (same size or bigger than the paper), cooking oil, plain water, dyed water (we used liquid food coloring), heavy paper (we used heavy sketching paper, but watercolor paper would be even better), large baking sheets, and eye droppers.
Place a small amount of plain water in the bottom of a shallow, rectangular baking dish. Use an eye dropper to maker droplets of oil in the water. I did this step myself, instead of asking one of my kids, because I found that William and Corinne were too heavy handed with the eye dropper and thus we ended up with a thick layer of oil on the water. Really, you only want a little because the more oil on the water the less color will show up.
You can choose to slightly mix the oil and water for a more marbleized effect, but we preferred to leave the oil in droplets on the water. Lay a sheet of heavy sketching or watercolor paper on top of the water and oil, then pull it out and place it on a large baking sheet.
Invite your child to choose a few coordinating colors of dyed water to use with the eye droppers to carefully place droplets of water onto the oiled sheet of paper. Your child will discover that where there is oil the dyed water will not be absorbed, thus not coloring that part of the paper.
Place finished masterpieces in the oven on a warming setting to dry more quickly. Once dried, iron the paper between two pieces of brown paper bag with a tea towel on top to absorb any extra oil. Finally, display or use. My kids made thank you cards out of them.