Name: Matthew
Message: What is the best way to "fix" the colors that I tie dyed onto my cotton shirt? I don't know the specific type of dye that we used, but someone said vinegar (is that an "old wives tale"?) and I'm not sure if that's the best solution. I would like to keep the shirt I made, but most importantly, I don't want the colors to bleed onto other items I may wash it with.

No, vinegar is not going to help. Whoever told you it would doesn't know what they're talking about.

The first thing you MUST do, if you care in the slightest about the fate of your shirt, is find out what dye you used! That's right, call the teachers or summer camp people or friends or whoever it is that bought the dye, and just ask them what brand or type of dye they used. It makes no sense to ask me, before asking the people who can give you the information you need before anyone can answer your question.

Did you use an all-purpose dye, such as Rit or Tintex brand all-purpose dyes? If so, you need to have heated the shirt while it was submerged in the dyebath, ideally for a minimum of half an hour at 190 degrees Fahrenheit or above. If you used all-purpose dye at room temperature, there is nothing you can do to save it, but if you boiled the shirt, all you need to do to improve washfastness is use a product called Retayne, from any good dye supplier or quilting supplies store. Retayne can be mail-ordered if your local quilt supply store doesn't carry it.

Or did you use fiber reactive dye, such as the Procion MX type dye used in most tie dye kits, such as those made by the Rainbow Rock and Jacquard companies? If so, and if you followed the instructions, using soda ash as directed, at or above 70 degrees Fahrenheit, then there is nothing further that needs to be done to fix the dye. You just have to wash out the unattached excess dye, by running it through one washing machine cycle in cold water without detergent (or with Synthrapol), and then a couple of cycles in hot water with detergent.

See the following pages in the FAQ section of my web site:
"How to Set Dye in Fabric"
"How can I fix the shirts I just tie-dyed with Rit® brand all-purpose dye so that they'll quit bleeding in the wash and stay bright?"
"My colors just washed out! What happened?"

Also see
"How to Tie Dye" and "Hand Dyeing - How to Do It: basic recipe for Procion MX dyes on cellulose or silk ".