Nature’s Mordant is a 100% plant-based mordant for dyeing textiles with natural dyes. It contains a proprietary blend of plant seed, gall, bark, and rind extracts that were selected to work together to help fix natural dyes to textile fibers. Nature’s Mordant does not contain any synthetic chemicals or industrial metal salts like potassium aluminum sulfate or stannous chloride.

Nature’s Mordant uses the tannins, minerals, and elements that are naturally present in a variety of plants to fix dyes to textile fibers. It is applied as a pre-mordant to natural fibers, which can then be rinsed and dyed.

Nature’s Mordant works with all natural fibers including wool, silk, and cotton. However, a slightly different method is used to mordant each fiber (see instructions on main page). Note that Nature’s Mordant will not work on synthetic fibers like polyester.

Based on our tests, Nature’s Mordant works with all natural dyes except for (a) Persian Berry Extract (which comes out very pale) and (b) orange dyes in general. Orange dyes like Coreopsis, Kamala, and Annatto may come out rather dull and brownish, especially on woolen fibers. This is likely because Nature’s Mordant does not draw out yellows as much as aluminum sulfate, causing orange dyes to look a bit flat (although annatto on cotton will come out a great neon orange!). We recommend Red Sandalwood for a good burnt orange shade on wool. The insect reds (cochineal and lac) work fantastically on wool and silk with Nature’s Mordant, but will only produce pinks on cotton.

Some dyes that work especially well with Nature’s Mordant include logwood (try Campeche Blue on wool or Royal Logwood on cotton), insect reds on wool or silk, Young Fustic Extract, and Wild Madder Extract.

Lightfastness will depend on the natural dye being used, but in general lightfastness will be similar to what you would expect from a standard aluminum mordant. For example, logwood blues dyed with Nature’s Mordant will fade to a grayish blue shade after one month of direct sun exposure. In contrast, madder dyed with Nature’s Mordant is exceptionally fast to light and barely fades after a month sitting in direct sunlight. If fastness to light is a primary concern some good choices include madder, cochineal, lac, weld, and cutch.

We recommend aiming for a light or medium shade of color with most natural dyes. Nature’s Mordant is a natural product and it does not have the same fixative power as, say, a strong concentration of aluminum sulfate. Trying to get too dark of a shade may simply result in wasted dye left in the dye bath, and fiber that is difficult to rinse.

Note that Nature’s Mordant does not perform well in hard water, likely because the lime (calcium) in hard water precipitates out the useful elements before they can attach to the fiber. Nature’s Mordant should work with most municipal water sources but if your water is very hard you might need to use an alternate water source.

Nature’s Mordant does not draw out yellows to the same extent as aluminum sulfate, so oranges may look a bit flat and yellows (though they turn out very nice and clear) might not be as strong as expected.

Nature’s Mordant tends to produce cooler shades of red than industrial aluminum or tin. To get a warm shade of red (for example with cochineal) you may want to add a tiny bit of a yellow dye like Old Fustic to the dye bath.