As summer comes to an end and many of our patrons are busy on vacation or getting ready to go back to school, we were eager to offer quick access to STEAM opportunities. One of our favorites is Sharpie Tie-Dye; it’s a low-cost experiment that takes just a few minutes but has a big impact in helping participants to gain scientific knowledge. Here’s what we did.
We first offered Sharpie Tie-Dye in the BOOMbox, Skokie Public Library’s STEAM learning space, and then created a to-go version to use on our Bookmobile this summer. We used small squares of neutral, natural fabrics like cotton, large plastic cups, and rubber bands along with Sharpie markers and two types of rubbing alcohol (50% and 85%) in dropper bottles. We followed this experiment from Kitchen Pantry Scientist, having learners first attach the fabric square to the top of the cup using a rubber band and then drawing a design. We asked learners to think about the colors they were using.
Next we had learners use droppers to saturate their fabric squares with rubbing alcohol, focusing the drops on the center of the fabric square. Then we observed. We asked learners what they were seeing. Most could articulate how the colors of their drawing were smearing or moving. We asked why they thought this was happening and then explained how this experiment was a version of chromatography, a chemical process that separates color pigments. Rubbing alcohol is a solvent and moves the color pigments through the fabric. Many marker colors are comprised of several color components, and as the rubbing alcohol moves pigments, different colors stop at different points along the fabric. Black markers are especially good for this.
If the learner has more time to explore, we encourage them to test different designs, like straight lines compared to filled shapes. We also have them try both percentages of rubbing alcohol, making a prediction about how the color pigment will move with a higher or lower percentage.
Our patrons loved this activity, and in preparation for the Bookmobile version, we made a how-to video to explain the entire activity. Watch our how-to video here and give it a try at your library.