Natural Dye Instructions for
Wool & Silk Fibers and Yarns

The instructions below are for natural dyes from Blue Castle Fiber Arts.

These natural dyes are from India, developed using a traditional fermentation process and come in a dried easy to use form. There is no need to follow different recipes or instructions depending on the plant material. All of our colors follow the same procedure. They can be used with any

mordant (although our favorite is the eco-friendly herbal mordant) and colors can be combined to give an endless range of shades.

The amount of mordant and dyestuff to use is based on the dry weight of fiber, or WOF. For mordanting, the percentage WOF is consistent but for dye color, the percentage is dependent on the desired shade. For example, 5-20% will give lighter shades, 20-60% medium shades and 60-100% very dark shades. It is recommended that you keep notes on the mordant used and quantity of dyestuff along with a sample of your dyed fiber. This will make it much easier to replicate a color.

For indigo you will often read that a special dye vat with a reducing agent is needed. It is a very interesting process but intimidating especially for new dyers. For wool and silk, our indigo-based dyes, Navy Blue and Forest Green, are used exactly the same as the other natural dye colors; no special process is required. In fact they are even easier since they don't even require the mordanting process. (They are referred to as direct dyes or substantive dyes. A mordant can be used to attain different shades and should be used if planning to blend with other colors that do require mordanting.)

Unfortunately, Navy Blue and Forest Green won't work with the cellulose fibers like cotton or hemp which do require the vat method. The other colors will work with cellulose but the shades will be lighter.

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Directions:

Start with yarn or fiber that has been washed and mordanted. If the material has been dried, re-soak it for at least one hour. Be sure to know the dry weight of the fiber since the amount of dye to use is based on a percentage of this weight. (See above)

Method 1:
Measure out the required amount of natural dye powder based on the weight of dyeing material and the desired shade. Mix with enough hot water to make a thin paste. Begin heating large pot of water (enough water to allow material to move freely) and add a small amount of vinegar or acetic acid to make the water pH 4.
When water reaches about 60C (140F), add the dye paste and stir well. Then add the pre-wetted fiber or yarn. Bring to a simmer, about 80C (180F) and simmer for 30 minutes, moving the fiber around regularly.
Remove from heat and allow to cool back down to 60C (140F). Remove material, drain and allow material to dry. (Yarn can be hung to dry; spinning fiber should be laid flat to dry.) Once dry, rinse fiber in a tub of warm water with a little soap to remove any excess dye and remaining dye particles. Rinse as needed in warm water. Dry material again (you can use the spin cycle in your washing machine to speed up the drying period although this is a bit risky with wool fiber which felts easily).

Method 2:
I have also used another method to make a dye bath that leaves less dye particles in the fiber to be washed out. Add the same amount of dye paste as Method 1 to a smaller pot of water, bring to a simmer, then remove from heat and allow particles to sink to the bottom. Pour off the dye liquor into a larger pot. Add more water to the smaller pot and repeat the process 2-3 times until no more colour is extracted. Discard the used dyestuff.
Let the dye liquor cool down, then add the prewetted fiber, slowly heat to back to 80C (180F) and simmer for about 30 minutes. Remove from heat and cool down. Material can be removed, cooled, rinsed and washed or it can be left in the dye bath for an extended period, ie. overnight, to allow as much dye take-up as possible. Then rinse, wash and dry.

Notes:
Unless using a superwash yarn or fiber, remember to handle wool gently so it won't shrink and felt. Temperature changes should be gradual, not extreme. Avoid excessive agitation and move wool gently in the dyebath and wash water. Non-wool fibers can tolerate more handling but be careful not to heat silk above 80C (180F) as it can lose its natural sheen.

Dye enough material for an entire project all at once (and then some). It can be difficult to replicate an exact colour using natural dye – part of the charm, fun and creativity but better to avoid the disappointment. If you don't yet have a knitting project planned, an average sweater in a DK or worsted weight yarn requires about 600 gm of yarn.

You can reuse a dyebath to get fiber/yarn of a lighter shade. Unfortunately, since you won't know how much dye is actually left, if you really like what you get you may never be able to replicate it. But it's a good way to use up all the dye.

Go to Natural Dye Catalogue