Marbling or marbleizing paper provides it a swirled, complex-looking finish that is difficult to create if you attempt to paint the colors on the hand. Marbleizing is a process similar to dyeing Easter eggs: Paint sits atop water, subsequently transfers onto objects dipped through the paint layer. The trick to making your own marbleized items is borax, which changes the surface tension of the water, allowing paint to float at the top. Paper works best with this technique, but it is possible to use card stock and other objects as well.
Cover the work surface using a plastic tarp, old dry-cleaning bag or plastic wrap to protect it from both spills and paint. Spread paper towels out above the plastic to absorb water after you dip items into the paint mix.
Fill a shallow plastic tub with a couple inches of water. Set the tub atop the plastic on the work surface. Mix in 1 tablespoon of borax, stirring with a spoon till the borax dissolves. Let the mixture sit for 30 minutes or so.
Squirt a drop of acrylic paint on the tip of a skewer. Touch the water surface using the skewer tip so the paint transfers to the surface of the water. It should float. If it doesn’t, scoop out the paint with a spoon before it mixes into the water and mix more borax into the water.
Squirt a drop of another color of acrylic paint on a fresh skewer, then touch the skewer to the water. Repeat the process with as many colors as you’d like.
Mix the colors atop the water by dragging a comb or skewer through them by blowing air across the surface using a straw.
Hold a sheet of paper so it is horizontal. Dip it down into the water, center portion first, then enable the sides to slide into the water. Pull the paper out carefully and permit the water to drip back into the pan. Set the paper, prettiest side-up, atop paper towels to dry.
Repeat Step 6 with various papers, card stock or bookmarks, adding and swirling more paint as required to make the colors brighter. The more items dipped into the marbleizing solution, the more often you will want to replenish the paint.