Separating Ink Colors using Paper Chromatography!

Project Overview:
Ever wonder if black marker ink is actually just black? In this project, you'll tinker with water and coffee filters to split ink into all the hidden colors mixed inside it! It's a unique and colorful way to explore how mixtures can be separated into their individual parts. WARNING: Some marker inks can stain clothing and surfaces, so work on a covered table and wear old clothes!

Materials:

1. Coffee Filters (cut into strips, each about 1 inch wide) or Strips of Paper Towel

2. Several Washable Markers (different colors, including black)

3. A Clear Cup or Glass

4. Water

5. Tape

6. Pencils or Wooden Skewers

7. Scissors

Instructions:

1. Cut the coffee filters into long strips, each about 1 inch wide if you aren’t use strips of paper towel

2. Draw a small dot with your marker about an inch from the bottom of each strip

3. Repeat this with a different colored marker on each new strip, including at least one black marker

4. Pour a small amount of water into the clear cup, only enough to reach about a half-inch high

5. Tape the top of each coffee filter strip or paper towel strip to a pencil or skewer, then rest the pencil across the top of the cup so the strip hangs down

6. Lower the strip until just the very bottom touches the water, making sure the ink dot itself stays above the waterline

7. Watch as the water travels up the strip and begins pulling the ink apart into different colors

8. Once the colors have spread apart and reached near the top of the strip, remove it and let it dry, then compare the results between markers

Explanation:
As you’ve learned from this experiment, marker ink usually isn't just one single color: it's actually a mixture of different colored dyes blended together! As the water slowly climbs up the paper strip, it carries the ink along with it, but each dye in the mixture travels at a different speed depending on how strongly it sticks to the paper versus how easily it dissolves in water. Dyes that stick to the paper more travel a shorter distance, while dyes that dissolve more easily and stick less get carried further up the strip. Considering that each dye separates out at a different point, you end up seeing all the hidden individual colors that were blended together to make the original ink color, which is exactly the same basic method scientists use to separate and identify different chemicals in a mixture!