Freshly rinsed textiles drying in the sun

Fabric Preparation Guide

Great dyeing begins before the dye bath

Beautiful color begins long before the dye bath.

Fabric preparation is the foundation of natural dyeing. From the cloth you choose to how it is cleaned and treated; each step directly affects how color is absorbed, held, and expressed.

Before questioning your dye, always return to your preparation.

Person holding cloth over a metal pot getting ready to scour fabric, on a stovetop.

Mordanting: Supporting Color

Mordanting is one of the most important—and often misunderstood—steps in natural dyeing.

A mordant is a mineral salt that helps bind dye to fiber, improving color fastness and often influencing the final hue. While many natural dyes require mordants to achieve lasting results, not all dyes depend on them in the same way.

Understanding when—and why—to use a mordant is key to developing both skill and intuition as a dyer.

Common mordants include:

  • Alum – brightens and clarifies color

  • Iron – deepens and softens tones

  • Tannins – support dye uptake on plant fibers

Mordants can also act as modifiers, allowing subtle shifts in tone from the same dye source.

Natural dyed fabrics in red, rust, and terracotta tones showing variation from 18th century natural dye dye techniques

Fiber Types: Know Your Cloth

All natural fibers fall into two main categories, and each requires a different approach:

Protein Fibers (Animal-Based)

Wool, silk, alpaca, cashmere

  • Sensitive to heat and agitation

  • Require gentle handling

  • Absorb dye readily

Cellulose Fibers (Plant-Based)

Cotton, linen, hemp

  • Stronger and more resilient

  • Require thorough scouring

  • Often need additional preparation for best results

Understanding your fiber is the first step toward predictable, lasting color

Scouring: Preparing the Fiber

Scouring removes oils, waxes, and residues that prevent dye from penetrating evenly.

For Cellulose Fibers

(Cotton, Linen)

  • Add washing soda to water (approx. 1–2 tsp per litre)

  • Simmer fabric for 60–90 minutes

  • Stir occasionally

  • Rinse thoroughly

For Protein Fibers (Wool, Silk)

  • Use mild, pH-neutral soap

  • Soak in warm (not hot) water

  • Avoid agitation and temperature changes

  • Rinse gently

Proper scouring creates a clean, receptive surface—essential for even dyeing.

Natural dye mordants in labeled kraft pouches including ferrous sulphate, gallnut extract, chestnut extract, calcium hydroxide, and PAS for textile dyeing.

Mordants are not only used to fix dye—they can also modify color.

The same dye plant can produce a wide range of tones depending on the mordant used. For example:

  • Alum often yields bright, clear colors

  • Iron deepens, dulls, or “saddens” tones

  • Tannins can shift color while improving dye uptake on plant fibers

In this way, mordants become part of the creative process, allowing for subtle variation and expanded palettes from a single dye source.

Muted grey natural dyed textiles showing subtle tonal variation from eco dye and mordant processes
Yellow natural dyed textiles displaying soft to vibrant tones achieved through natural dye methods

Further Study

For a deeper understanding of mordanting and dye chemistry, we recommend The Art and Science of Natural Dyes by Catherine Ellis and Joy Boutrup.

Engaging in a dedicated natural dye study or workshop will further develop both technical skill and creative

Natural dyeing is a balance of preparation, process, and intuition.

When your foundation is strong, colour has the freedom to fully emerge

Join a Shibori or Botanical Print Workshop
Put these preparation techniques into practice

Yellow natural dyed textiles displaying soft to vibrant tones achieved through natural dyeing methods