The dye you will be using is called Procion. It is a fairly safe, easy to use, and very color-fast, bright dye when used correctly. It’s available from Dharma Trading Company in San Rafael, CA. Their order number is 1-800-542-5227. They have a very good catalog that also carries a wide range of dyeable cotton clothing. Their instructions for tie-dye are unnecessarily complicated, however. These will work just fine. For batches of less than 50 shirts, the 2-ounce container of dye will be more than enough. When working with children, I recommend using no more than 3 or 4 colors: Red, yellow, and blue can be mixed by the children to create almost any other color. I’ll sometimes add a deep purple such as plum as well.
    NOTE: Procion dyes come in powder form. Though they are not very dangerous (though of course, observe some degree of caution-- they shouldn’t be ingested, for example) all powders can potentially cause respiratory irritation, so use of a dust mask (the cheap paper kind is fine) while mixing the powders is recommended. Also, the dye will stain your skin so gloves should be worn whenever you are in contact with it.
    Dyes can be mixed with ordinary hot tap water. The usual ratio is 3 teaspoons of dye powder for each squirt bottle. Some colors, such as Turquoise, suggest twice this amount for maximum color yield. These colors are identified with an * on the Dharma color chart. I find that this is rarely necessary for primary colors, however. Put the dye powder in the bottle, then fill it with hot tap water, cap it, put your finger over the hole, and shake it up. That’s it! The dye is ready to use. Dyes will keep indefinitely in powder form, but only about a week once they are mixed.

    Procion dyes are pH sensitive: They require an alkaline pH to set. In order to accomplish this, the shirts must be pre-treated in the Washing Soda (calcium carbonate) Set your washer for a small load, then fill it with hot water. Dissolve a full box of Washing Soda as the washer fills. Let it agitate just long enough to dissolve the Washing Soda, then add the clothing to be dyed and agitate for 5-10 minutes. Let the washer drain and spin out, but do not rinse. The clothes are now ready to be tied and dyed. NOTE: The washing soda will make your hands feel a bit slimy, and will taste bitter so discourage children from putting their hands in their mouths without washing them first.

    Pass out rubber bands and let the children go wild! Kids do amazing things with very little adult guidance. For very young children, an effective technique is to gather smooth, round rocks and rubber-band them into the shirts. The rocks will leave sunburst patterns no matter how the dye is applied. Experiment with other objects, too--ping-pong balls, marbles, let the children use their imaginations. Make sure that the objects are smooth, though, or they may tear the shirts. Older children might want to try paper fan folds or experiment with symmetry. Adults can help children make sure the rubber bands are secure, but not too tight to remove easily. The important thing to remember is there is no wrong way to do this! HINT: Tying is easiest on a smooth surface like a table or a tarp.

    This part is best done outside if possible, since it can get rather messy. I like to spread newspapers on the ground in a circle, clean paper for each child, and place the dyes in the middle. Make sure all children are wearing smocks or clothes which can get stained and a pair of rubber gloves. Put the shirts on the newspaper and go wild! Some children like lots of dye, and you need to take care that it doesn’t puddle. Others are more cautious and very particular about where each color should go. Again, there is no right or wrong way to tie-dye. Lots of colors will look great. Children should know, though, that it’s hard to predict what the shirts will look like when they’re done. When one side of the shirt is nearly completely colored, help the child to turn it over and do the other side. If the paper has puddles of dye at this point, replace it with clean paper. When the shirt is finished to the child’s satisfaction, put it in a ziplock baggy and put it aside. That’s it for now!

   The dye needs to set overnight, preferably for 24 hours, before it can be rinsed out.

    Any kind of laundry soap will work fine for this provided it doesn’t have bleach in it! Dharma does carry a very good soap called Synthrapol, which is worth investing in if you plan on doing this a lot, but if you’re only doing it once in a while, it’s not worth it.
    Put your gloves back on and begin to untie the shirts. You can pile them on top of one another at this point-- it won’t stain them because any additional dye which gets on them won’t have time to set. Put them all through a cold wash/cold rinse cycle first. Then add more soap and put them through two hot wash/hot rinse cycles. Check the water during the last rinse-out. If it’s still quite dark, do another hot wash. If not, do a final cold cycle, then machine dry them. That’s it! Your shirts are color-fast and can be washed normally.

    Good luck! It’s not hard and can be lots of fun. If you have any questions, please feel free to call me at the number on the first page. Happy dying!