Natural Black & Grey Dyes

There is no single "black" plant. Natural greys and blacks come from a simple reaction: tannin plus iron. Tannin-rich plants such as oak galls, sumac, black walnut hulls and pomegranate peel turn grey to charcoal when they meet iron (ferrous sulfate). This is the same chemistry behind historic oak gall ink.

How to get grey or black

  • Silver grey: a light tannin bath, then a weak iron afterbath (about 0.5–1% WOF).
  • Charcoal: a strong tannin bath (15–20% WOF oak gall), then iron at 1–2% WOF.
  • Near-black: repeat tannin and iron layers, or start on a mid-blue indigo base.
  • Warm browns and khaki greys: walnut, pomegranate, red pine bark or acorn extract with iron.

Use the natural dye WOF calculator to turn these percentages into grams for your fabric.

Fiber tips

Cotton and linen take tannin and iron very well. On wool and silk keep iron low (1% WOF or less) because more iron can make fibers harsh and weak. Always rinse well after the iron step.

Explore more: Natural Tannins · Alum & Iron Mordants · Brown Dyes

Frequently asked questions

What natural dye makes black?

Black comes from tannin plus iron. Dye with a tannin such as oak gall, sumac or walnut, then use an iron afterbath. Layering, or an indigo base, gives the deepest black.

Is iron safe for fabric?

Yes, in small amounts. Use 0.25–2% WOF as an afterbath. On wool and silk stay at 1% or less to avoid harsh, weak fiber.

Why is my natural black fading to brown?

Usually too little tannin, too little iron, or poor rinsing. Build the color in several thinner layers and rinse well between steps.

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