FAQ: My colors are not very bright. What did I do wrong?
The most common cause of unsatisfactory dyeing is choosing
the wrong sort of dye. For example, cotton dyes will not dye
polyester, and all-purpose dyes are never very bright on
cotton. See "About Dyes and "What
kinds of dyes are there?".
Yes, but I was using good fiber reactive dye on cotton,
and my colors came out too pale anyway!
Most people obtain very bright colors with fiber reactive
dye, such as Procion MX type dye, but
now and then something goes wrong.
You may have dissolved the dye in hot water - never dissolve
Procion MX type dyes in hot water, as the dye will simply react with
the water immediately, leaving no reactive dye to bind to your fabric.
Room temperature water is best.
You may need to leave the dyeing reaction longer. Some people find
that for them it is necessary to leave the fabric to "batch" for 24 to
72 hours (though I usually find 8 hours to be quite sufficient).
The material must be wet the entire time the dye
reaction is occurring. The reaction will stop when the material is dry.
Use plastic wrap to cover the wet fabric, or, in humid areas, add
urea, which is a humectant, to help maintain
moistness - for the latter, see What
is urea for? Is it necessary?
You can also add more dye, or use more urea to help dissolve more dye.
Too much urea can actually reduce solubility of some dyes, however,
particularly fuschia (red MX-8B). You must add twice as much, by volume,
of turquoise (turquoise MX-G) or mixtures that contain it, to get a
similar intensity of color, and up to four times the usual dye
concentration for truly satisfactory blacks.
For vat dyeing Procion-type turquoise MX-G, higher temperatures work better (45
degrees C), as does substituting glauber's salt (sodium sulfate,
available from most of the companies listed under Sources) for regular salt,
if you use salt.