Persian Berries (Buckthorn) Dye: 6 Mordant Methods Compared

A guest post by Mirjam Gielen, an embroidery artist who uses eco-dyed threads on eco-printed fabrics. You can find her on Instagram as @mirjamtextiles.

At the request of themazi, I dyed a set of samples with buckthorn to show how different mordant methods change the color result. Some of the fabrics came from themazi; I made samples on cotton and on linen-cotton blends, which are excellent for embroidery. I also added a white linen and a wool. All the fabrics are organic, so some have a natural ivory or beige color, which can make some samples slightly darker. I did not use silk, but the results would probably be similar to wool.

All fabrics were washed with a pH-neutral detergent before mordanting and dyeing. I used a dye bath of 15% WOF buckthorn, and that turned out to be enough for saturated colors with most mordant methods.

Editor's note (themazi): the dye used here is our Persian berry powder, ground Turkish cehri berries. For names, history and full recipes, see our Persian berries dye guide, and work out amounts with the natural dye calculator.

The six mordant methods

1. No mordant (top left)

A piece of linen with no mordant. It has the lightest color, and it will also be less light- and washfast than the mordanted fabrics.

2. Alum and cream of tartar on wool (top right)

I mordanted the wool with 15% alum and 7.5% cream of tartar. Wool takes up color easily, so it is no surprise that this gave the darkest color: a sunny yellow-orange.

3. Soy milk (top middle)

Soy milk is a cheap and easy way to prepare plant fibers for dyeing. To learn more about this method, visit Rebecca Desnos or The Barefoot Dyer.

4. Alum and cream of tartar on cotton and linen

On cotton and linen, alum and cream of tartar usually give paler results than on animal fibers such as wool and silk. A tannin bath first improves the result. I chose oak gall because it is very high in tannin, and used themazi's white oak gall powder.

5. Oak gall and symplocos (bottom left)

Symplocos is a plant that accumulates aluminum from the soil, so it can be used as a plant-based alternative to alum. I used an oak gall bath at 20% WOF and symplocos at 50% WOF, and the results were excellent. This method is very sustainable, because both mordants come from renewable sources. Both leave a slight yellowish tone on the fiber. Oak gall reacts with iron, so keep the fabric away from rusty objects. The color of symplocos does not seem to affect the final result.

6. Oak gall and aluminum acetate (bottom right)

Apart from the wool, this combination gave the best and most saturated colors. Aluminum acetate works better than potassium alum on cellulose fibers such as cotton and linen. It can be hard to find (I could not find it in the Netherlands, where I live), but you can make your own inexpensively. I learned how from The Art and Science of Natural Dyes by Joy Boutrup and Catherine Ellis, a book I warmly recommend because it is packed with information about natural dyes and mordants. A short recipe is also in themazi's guide to mordants.

Which method is best for you?

It depends on your circumstances, your values and the result you want. The methods range from simple (soy milk) to more involved (tannin and aluminum acetate), and from fully renewable (tannin and symplocos) to cost-effective (alum, or tannin and aluminum acetate). I am very pleased with the range of warm, bright yellows that buckthorn gave me, and it has quickly become one of my favorite dyes.

Frequently asked questions

Which mordant gives the strongest buckthorn yellow?

In this test, alum with cream of tartar on wool gave the darkest yellow-orange. On cotton and linen, oak gall tannin followed by aluminum acetate gave the most saturated color.

Can I dye buckthorn without a mordant?

You can, but the color is light and less light- and washfast. A mordant is recommended for lasting color.

How much buckthorn powder was used?

A 15% WOF bath of Persian berry (buckthorn) powder was enough for saturated colors with most mordant methods.

Is symplocos a good alternative to alum?

Yes. Symplocos is a plant that accumulates aluminum. With an oak gall tannin bath it gave excellent results on cotton and linen in this test.

Related: Shop natural yellow dyes · Mordanting wool and silk · Mordanting cotton and linen