Here, the stain-removing power of bleach is used to create a negative-image design that subtracts color and adds fun. Bleach is strong stuff, so while working on this project, wear old clothes and rubber gloves, follow safety precautions on the label, supervise kids closely, and work in a well-ventilated area.
Wash and dry the shirt, then slip a piece of waxed paper inside it to prevent bleed-through.
Sketch your design on the shirt with chalk. Because the bleach can spread, keep the design simple, and draw with lines and dots, as shown, rather than try to fill in large areas.
Shake the bleach pen and give it a few test squeezes on a paper towel to make sure it's flowing well. Trace over your chalk lines with the bleach pen. Leave the bleach on the shirt until the fabric has clearly changed color. This can take anywhere from 10 minutes to 2 hours, depending on the shirt. Wash the shirt by itself in the washing machine, then dry it.