Iron Mordant and Modifier for Natural Dyeing, Ferrous Sulphate


Iron Mordant and Modifier

Iron (Ferrous Sulphate) can be used in natural dyeing as either a mordant, to fix colour to fibre, or as a modifier, to change the tone of a naturally dyed colour. When iron is used with natural dyes, it tends to "sadden" the colours, or darken them towards grey/brown.

In the samples in the last image, the top row was mordanted with iron, while the bottom row was mordanted with alum (another mordant used to brighten colours). Each column is dyed with the same plant; from left to right, marigold, cochineal, and madder root.

Most natural dyes need to be used along with a mordant in order to help the colour attach to the fibre.

Available in 20g or 40g quantities in recycled paper envelops.

Use iron at 2% of the dry weight of fibre (WOF). (Eg. For 100g of fibre, use 2g alum.)

Equipment and Saftey

Pre mix each dye vat ingredient in small containers of water to avoid lumps. Always add powder to liquid, not liquid to powder (to prevent powder from flying everywhere). Wear gloves and an apron to avoid staining your hands and clothes. Always dye in a well ventilated area and use separate pots and utensils from your cooking pots.


I accept payment via PayPal, credit card and Etsy gift card. If you'd like to discuss another method of payment, please send me a message.

As soon as I receive your payment, I will prepare your Westlake piece to be shipped out to your mailing address.

Shipping from Canada

I am the only knitter behind Westlake, so please allow 5 days for me to knit, package and mail out your handmade goods. Thanks in advance for your patience!

In order to ensure that your Westlake piece reaches you safe and sound, each smaller hand knit item comes swathed in a bubble envelope. Larger orders will arrive in sturdy poly-mailers.

I package and ship items through Canada Post's regular air mail service, which means that, once mailed, your Westlake item should reach your door in:

- 2 to 9 business days (within Canada)
- 6 to 14 business days (within the USA)
- 6 to 21 business days (international)

This is the most economical shipping option, and so it unfortunately does not come with a tracking number or delivery guarantee. If your item hasn't arrived within the above timeline, please get in touch.

If you would like your package sent Express (comes with a tracking number and delivery guarantee), please get in touch and I would be happy to send you alternate shipping rates.

Please note that International and US parcels may be subject to customs fees at the border, depending on the country you're in, the value of the item and, well, luck (the process seems to be random). Unfortunately, this is out of my control, and I cannot be responsible for paying the fees. You can find out specific fees and duty free thresholds from your local postal service.

If you live in Toronto as well, feel free to contact me about pick-up options.


If for some reason you aren't satisfied with your hand knit Westlake piece, please contact me and I will do my very best to resolve the problem.

If you would like to refund or exchange your Westlake Design, it must not be worn or damaged. As soon as I receive the item, I will refund its cost minus the original shipping charge. Unfortunately I cannot be responsible for covering the shipping charges for returned or exchanged items.

I package my items with care, but if for some reason your Westlake Design was damaged in the mail, contact me as soon as possible to arrange an exchange of the item. Please take a photo of the damaged packaging before opening.

As a small business owner your feedback is very important to me! I would really appreciate the opportunity to make your shopping experience a positive one so please contact me with any concerns before leaving feedback.


I do my very best to take pictures that show an item's colour accurately, however colours may appear different on different computer monitors.

Feel free to contact me regarding custom orders, questions, or comments. I'd love to hear from you!

Je parle un peu de français aussi, donc n`hesitez pas de m`addresser en français! Je ferai de mon mieux de répondre en français mais je ne peux pas promettre la grammaire parfait:)

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