Name: henny
Message: I read an answer on the blog written by you....you're enormously knowledeable! I am at the beginning of a textile and surface design degree and would like to know what you would recommend for me to read on the ways to dye different types of fabric....the ph values etc. For example I have tried to dye my devore two tone with a procion and an acid dye mixed together...I used both acid and procion fixatives and think this must have been why my devore was just one colour!! :( instead of two tone. Also I can't get my polyester satin to dye at all!! So what would you recommend to increase my knowledge? Thank you so very very much for your time and help.

The book I most recommend for serious students of dyeing is Giles's Laboratory Course in Dyeing. See the 'Scientific and technical books on dyeing' section at the bottom of my page of book reviews. Order this book directly from the website of the Society of Dyers and Colourists. I also strongly recommend David M. Lewis's book, Wool Dyeing, John Shore's books, Cellulosics Dyeing and Blends Dyeing, from the same source. They each cost £9, very reasonable considering how valuable they are. [Update 1/05/2010: the prices have since increased to £35 and £29, plus shipping; the books are still worth their cost, but no longer so inexpensive.]

Also, get yourself some pH paper as soon as you can. Your dye supplier should carry this, or look for a supplier for chemistry teachers. Buy a wide range pH paper that covers the whole range, from a pH of 1 or 2 to a pH of 13 or 14. If you prepare your dyebath with every ingredient except for the dye itself, you can test its pH, and know just what you're getting into. Doing this on a number of mixtures and household chemicals is probably the fastest way to get a good feeling for how pH works. You want a pH of 10 or 11 to fix fiber reactive dyes on cotton, rayon, or other cellulose fibers, and a pH of 4 to 6 for an acid dye for a protein fiber such as silk or wool, depending on the class of acid dye you are using.

Using both the acid fixative for acid dyes and the soda ash fixative for fiber reactive dyes would give you a neutral pH, which won't fix anything at all! Pick just one fixative to use at a time.

Actually, Procion MX and other fiber reactive dyes will act as acid dyes when used with an acid pH. Fiber reactive dyes are constructed like acid dyes, but with an added reactive section that can form covalent bonds to the fiber molecule. See "Fiber reactive dyes on protein fibers".

Complicating things further, silk dyes very well with fiber reactive dyes at a pH of 10 or 11, with soda ash. You do not dye wool at a high pH like that only because it would be damaged. Nylon cannot be dyed at high pH, but silk and wool can be, since they are more complex, chemically, than nylon is. They are all polyamides, but the natural protein fibers contain many amino acid side chains, as well, which are not found in nylon.

To dye devoré two different colors at once, one color on the silk and another color on the rayon, you have two choices. One is a rather overpriced system called Alter Ego, made by the H. Dupont company. In the UK, one good mail-order source is Fibrecrafts. It contains an acid dye to dye the silk but not the cellulose, a direct dye which dyes both silk and cotton, and a reserving agent which prevents the direct dye from dyeing silk. You can choose contrasting colors to dye the two different fibers in the blend. The other option, less predictable and also less expensive and more washfast, is to use two or more colors at once of Procion MX dye, with soda ash, using two colors which 'take' to different degrees of efficiency on silk and on cellulose. See these three discussions on the Dye Forum: Dyeing silk/rayon blends two different colors, "Alter Ego" dyes and dyeing rayon/silk velvet devoré. If you use acid dyes to dye only the silk component of the blend, keep in mind that they may stain the cotton, and apply in a separate step, before the fiber reactive dyes.

To dye polyester, you must use disperse dye, not any other type of dye. You will need to buy this dye by mail-order. See my list of Sources for Dyeing Supplies Around the World. For more information about dyeing polyester, see "Dyeing Polyester with Disperse Dyes". A good book to consult is Holly Brackmann's The Surface Designer's Handbook .