Faded colors & what is the point of salt?
  • I'm doing something that is basically tye-dyeing without the rubber bands. I got old white 100% cotton sheets from the thrift store & sewed them into napkins. I soaked them in the soda ash stuff for almost an hour (I was doing other chores & figured it's not ultra critical), then I spread the napkins in the sink, sprinkled on mx powder, & scrunched them up so the dye would spread in varying levels of intensity. (This irregular pattern helps hide the inevitable stains cloth napkins get.) Put in plastic bags overnight, washed just now with a mild soap in hot water in the machine. They came out more faded than I think they should be.

    I spent a while reading the diff directions on this site for tie dye, immersion, etc, & see that sometimes salt is used. in the immersion instructions, one uses more salt for darker colors, suggesting that salt helps bind the color. If so, why does the bottle not suggest it for tie dyhing? Any thoughts on how to keep my colors brighter? I know it's possible, & I'm doing everything according to what I can find. Thanks.
  • You don't need salt with Procion MX dyes unless you're dyeing with a high volume of water, as one does for dyeing smooth solid colors. In that case, it does not help bind the color, it just helps the dye get close to the fiber, where it can react, which is a problem only with large volumes of water, not for direct application such as you were doing. See "Do I need to use salt, in dyeing?". Some people do use salt in tie-dyeing, but most do not. I like to use it in low water immersion dyeing to increase the complexity of the patterns, but in that case it does nothing to increase the final intensity of the dye colors, since my dye concentrations are already plenty high.

    The material you used for your napkins is probably either 50% polyester (sometimes the labels are wrong!), instead of the 100% cotton you expected, or else, like most sheets, treated with wrinkle-reducing resins that tend to resist dye. Other possibilities include a reaction temperature below 70°F, old dyes, or accidentally substituting urea for soda ash. There's also a list of various ways to make colors as intense as possible here.