mordant tests, textiles

Testing Mordant Recipes for Cellulose Fibers

I’ve been practicing natural dyeing for 16 years and I have avoided delving deeper in dyeing cottons and linens all along the way. I’ve dabbled in it but I never had a lot of conference in what I was doing. Just playing around seems more accurate to describe my approach when it comes to dyeing these fibers. Wool and silk have been my primary focus for years.

There is so much information out there now on natural dyes with people everywhere experimenting and it can be hard to know where to start if you want a particular result.

So I spent some time with my natural dye book collection and combed through all the mordant recipes for cottons and linens I could find that were different from each other. I made a hand written spread sheet, did some math and set up tests in miniature.

I snipped the tiniest hole in the cloth to correlate the number given to each recipe.

The column of cloth to the left is cotton. Column to the right is linen.

Starting from the bottom on each side with 1 hole in the corner of the fabric is the following recipe- loosely. I’m not going to give exact measurements or ratios as my notes are everywhere and this can be figured out with whatever recipe you decide to go search for and choose. This is just to give a basic idea of what mordant does what and for how long.

1). Alum 15% WOF (weight of fiber) cold soak 24hrs.

2). Tannic acid cold soak 24hrs, followed by an alum cold soak 24hrs.

3). Alum acetate (about 20 years old(!)) cold soak 24hrs.

4. Alum acetate (bought fresh) cold soak 24hrs.

5. Alum cold soak 24hrs, followed by a tannic acid cold soak 24hrs, followed by an alum cold soak 24hrs.

6. Alum heated to boil for 1hr, cooled, tannic acid heated for 1hr, cooled, followed by alum heated to boil for 1hr, cooled.

All dyed in the same pot with ground cochineal.

The winner for me is either acetate. It seems to give the strongest and most consistent color and I loved that I leave it to soak. Set up and forget it.

I do enjoy the tannic acid and alum cold soak but that extra step of doing alum, tannin, alum seems to not measure up for me compared to just tannin followed by alum.

The just alum cold soak is the fairest of them all and I won’t rule it out for using. It did give the cochineal more of a yellow tone in the red which is nice compared to the violet tone of all the others. Yields a different shade and is a cheaper mordant to use.

The tannin, alum soaking methods could also be used by using tannin rich plants instead of dealing with the powered form which I plan on doing in the future when I run out of both acetate and tannic acid.

All in all a super fun project for me and now I have better information to help inform my dye decisions.

What’s your favorite?

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