What makes colored ink separate into this cool multicolored sun burst? We've got the answer. I'm Lee Woodruff at the craft table with Family Fun. You can turn any room into a science lab with this fun and fascinating home experiment.
You'll need a basket type coffee filter, a quarter or bottle cap, a green water soluble marker, in other words not a permanent marker, water, plastic cups, and a rubber band. Spread open the paper filter on a protected table. Place the bottle cap in the center of the filter and draw a circle around it with the marker. Fill one cup with water and then set the other cup on the table and stretch the filter over the plastic cup. Use a rubber band to secure it. Dip your finger in the water, then touch the center of the circle with your wet finger tip. Watch the wet spot on the filter until the ink stops spreading. So what makes the filter turn different colors? Ink is a mixture of fast drying liquid and pigments. The pigment of the dry marker ink on the paper filter dissolves in the water and is absorbed by the surrounding filter paper. But the different colored pigments have different levels of interaction with the paper. The color with the least attraction moves the farthest, usually blue pigments move farthest. Now try other colors, but avoid primaries. See what happens with black ink. Who knew that science can be so pretty?