Name: Catherine

Message: I am going to be cheeky and ask you a question direct, I hope you don't mind, I am getting a little desperate and I have just been told that you are the queen of all dyeing knowledge. Promise I will use the forum next time...I tried dyeing sinamay with acid dye which turned out very badly. I was informed that I should be using Procion dye and so tried that this morning. It was going very well, the colour was just what I wanted until I dried the sinamay. I hung it on the line - just for 10 minutes in the weak Welsh sun - and it changed colour, from a lovely red violet to a much bluer colour. It also went very dull and flat and the colour was very patchy. There are remnants of the original colour where the pegs were which made me wonder if it was the sun but I have been advised that its unlikely. I actually got pretty much the same disasterous result as when I used the acid dye.

I wonder if you'd do better to use a fabric paint, instead of dye. You can correct the color of the Procion MX fiber reactive dye on your sinamay by dyeing it again with a fuschia or magenta Procion MX dye, but it will still suffer from the patchiness and the alteration to the surface sheen.

You might be able to correct the dullness by spraying on a shiny acrylic coating, such as is used as a fixative for chalk or pastel drawings, or by applying a polyurethane varnish. Look for the pastel fixative at an arts or crafts store; look for polyurethane varnish at a hardware store. Ordinary spray paint is no good at all for most fabrics, because it makes the material stiff and scratchy. Would it be a problem if your sinamay hats are a little stiff and scratchy? It seems to me that the stiffness might be a good thing, and th scratchiness not an issue, on a hat. I am only afraid that some non-fabric-type paints might crack or peel when the material is flexed. It is important to use only fabric paints when painting on fabric used in garments, because of the scratchiness issue with ordinary paints; fabric paints are softer, and also more flexible.

Since sinamay is a cellulose-based fiber, it ought to dye well with Procion MX dye, but whether it will dye splotchy, rather than smooth, depends on the preparation of the fiber. Fibers that are not sold specifically for dyeing may have oils or waxes on them from the manufacturing process, or may have had surface finishes added which will interfere with the dye's ability to penetrate the fiber. It is important to prewash material in hot water before dyeing it; this will remove some but not all of the finishes or oils that can interfere with dyeing.

If the sinamay was stiffened before you acquired it, it probably contains synthetic polyvinyl alcohol glues which will be impossible to completely remove, and which will prevent the dye from penetrating. In this case, I think that spraying on fabric paint or regular spray paint will be your only options.
 
The color change after you hung the hat on the line is probably meaningless. Some dye colors change temporarily in the high pH of the soda ash. This is insignificant and temporary, although it looks dramatic. See, for example my Dye Forum post about boysenberry Procion MX dye:
"boysenberry MX dye turns red with high pH". After you have completed the dyeing, restore the pH to normal by just washing, or if necessary by washing and then rinsing in a very dilute mixture of vinegar in water. Some water supplies require a bit of distilled white vinegar in order to lower the pH of the water to neutral.

It is also possible that some dullness is caused to the sinamay, by either permanent damage from the soda ash, or by the temporary high pH. See whether the vinegar rinse helps restore the sheen of the sinamay. Also try an unscented fabric softener to see if it restores the sheen; the best fabric softener is sold by dye suppliers, but I don't know whether your supplier carries it.

Procion MX dyes work best at a pH of 10.5 to 11, though this varies by the fiber, but they will work even at a somewhat lower pH. If the dilute vinegar after-rinse does not help maintain the sheen of the sinamay, try using a much smaller amount of soda ash, or mix soda ash with baking soda. Do not omit the soda ash, because Procion MX dye does require a pH of at least 8 or 9 to work at all.

The remaining alternative for dyeing would be a direct dye. Direct dyes are poorly washfast and make an inferior dye for cotton, but this might not be a problem for a hat. Also, there is a dye fixative, Retayne, which can make direct dyes acceptably washfast, though it increases lightfading. Deka L is one brand of direct dyes. There is also direct dye (mixed with useless acid dye) in the mixture known as all-purpose dye. Brands of all-purpose dye include Rit dye, and Dylon Multi Purpose (but no other line of Dylon dye - the others, including Dylon Cold Dye, Dylon Permanent Dye, Dylon Hand Dye, and Dylon Machine Dye, are all fiber reactive dyes).


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