Back to Mordants and Additives
Oxalic acid
$6.00 – $10.80
Used occasionally as an ASSIST in natural dyeing. Oxalic acid will alter the shades of cochineal dyebaths, pushing them towards brilliant orange-red.
Also used to help absorption of Tin when premordanting. Dissolve with the tin in hot water at 2% WOF then add to premordanting water, mix and enter fibre.
TO USE: with cochineal baths, use at 2% WOF (weight of fibre). Dissolve first in hot water then mix into dyebath before entering fibre.
Dispose of spent dyebath on the ground.
CAUTION: POISON!!! Wear a mask when handling powders, absolutely wear gloves at every stage with Oxalic acid. MUST BE DONE OUTDOORS: fumes can be an extreme irritant.
Related products
Urea (Ammonium nitrate) – 250g
Price per 250g (8.82 oz) container.
CANADIAN SHIPPING ONLY. Limit of 1 per order. We stock Urea in larger packs, including 500g and 1kg sizes available for pickup at the shop only. PLEASE CONTACT US for availability and prices: [email protected]
Due to the potential use of urea as an ingredient in explosives, we wish to handle the distribution of it carefully. Absolutely NO international orders!
We also cannot, by law, supply Urea to those wishing to use it as a nitrogen fertilizer for home garden or agricultural application.
Used mainly with synthetic dyes as an ASSIST, urea helps to open up fibres and allow for better dye penetration, and also keeps the fibre wetter for longer during direct application of dyes. This is a soluble form of urea that dissolves easily in hot water.
TO USE: Follow any of the dyebook directions for cold pad batch dyeing.
Dispose of spent dyebath in the usual way, most likely down the drain.
CAUTION: Should be used with good ventilation. Wear a mask when handling powders. Wear gloves.
Alum (Aluminum sulphate)
Used as a MORDANT in natural dyeing, which allows the plant pigments to bond with the fibres.
This is Potassium aluminum sulphate, the preferred form of alum for use as a mordant. This IS NOT pickling alum and should not be consumed.
Used mainly on protein fibres such as wool, alpaca, silk. Usually used in combination with cream of tartar. Many natural dyers do a premordanting of the fibre with alum, while others add it directly to the dyebath (particularly with loose fibre such as fleece). Also sometimes used in combination with tannic acid to premordant cellulose fibres such as cotton.
TO USE: calculate mordant required for 8 to 15% WOF (weight of fibre) and 4 to 6% WOF cream of tartar. Weigh and dissolve in hot water. Fill pot with sufficient water for the fibre to move, add alum and cream of tartar and stir. Enter fibre. Bring to 180-200°F and hold 1 hour. Stir yarns frequently but fleece only occasionally. Cool overnight, then wash in soapy water and rinse thoroughly. Dye immediately or dry the yarns to dye later.
Spent mordant solution may be safely disposed of down the drain (except for septic systems). It also may be poured around garden plants that prefer acidic soil conditions.
CAUTION: wear a mask when handling powders. Wear gloves when using alum, particularly when rinsing or handling wet yarns as it is very drying to the skin. Best done outdoors or with very good ventilation.
Myrobalan, Ground
Ground nuts of a tropical tree, Terminalia chebula.
Use on protein or cellulose fibres. Considered both a mordant and a dye, because of the high tannin content. Yields a light butter-yellow to beige or mushroom. Substantive, no mordant needed. Use at 15-20% WOF as a mordant on cellulose fibres. As a dye, use at 20-30% WOF for medium shades.
TO USE:soak 24 hrs in water to dissolve. Add more water if necessary and enter fibre. Bring to a high simmer for 1 hour. Let fibre cool overnight.
Light and washfastness: good.
Iron sulphate
Used as a MORDANT in natural dyeing, which allows the plant pigments to bond with the fibres.
Iron darkens or "saddens" colours. It takes only a tiny amount to do this, and one must be careful with iron: too much will harshen or damage fibres. If you use iron with any regularity, consider having a dedicated pot for this purpose, as it sticks to pot surfaces and will affect the colour of future dyebaths. A chipped enamal pot is perfect.
Used mainly on protein fibres such as wool, alpaca, silk. Although it can be used as a premordant, most natural dyers use iron to alter the colour at the end of the dyeing process. If you prefer to premordant, follow the usual steps using iron at 6% WOF.
TO USE: Weigh fibre before wetting. Dye in the bath of your choice, with or without an alum premordant. Calculate iron mordant required for 2% WOF (weight of fibre). Dissolve iron in hot water. Remove fibre from warm dyepot, stir in dissolved iron and re-enter fibre. Simmer for 5 minutes, cool then wash and rinse well.
Spent mordant solution may be safely disposed of by pouring in the garden. Iron sulphate is a common soil amendment in agriculture and horticulture.
CAUTION: wear a mask when handling powders. Wear gloves when using iron, as it stains skin easily. BEST DONE OUTDOORS or with very good ventilation. Avoid breathing fumes.