Keeping a Dye Journal for Repeatable Results

Why a Dye Journal Earns Its Keep

Natural indigo is not a product you buy and pour. It is a relationship you build with a vat, and like any relationship it has moods. The same recipe that gave you a deep midnight blue in a cool March workshop can throw a thin, greyish teal in a humid August kitchen. Three weeks later, when you want to match that midnight blue for a patch on a linen shirt, memory will let you down.

A dye journal is how you stop guessing. It turns a happy accident into a recipe you can return to, and a strange result into a lesson you can name. For anyone who dyes with slow stitching in mind — a quilt, a length of sashiko, a mended cardigan — this matters twice over. You cannot match a colour to a garment months later if you never wrote down how you made it.

Record the Set-Up Before Anything Gets Wet

Most disappointing dye sessions are decided before the fibre enters the pot. Note the following before you begin:

• Fibre and weight. "Cotton" is not enough. Write down whether it is scoured, mercerised, recycled, or a wool and linen blend. Weigh it dry, in grams, because every quantity that follows is a percentage of that number.
• Water. Hard water in parts of southern England will dull some dyes and shift others. Note whether you used tap, filtered or rainwater, and whether you added a softener.
• Scouring and mordanting. Record the mordant, its percentage of weight of fibre (WOF), the temperature, the time, and any afterbath. Alum at 15% WOF with 7% cream of tartar is a common starting point for cellulose, but write down what you actually did, not what you meant to do.
• The day itself. Room temperature, weather, whether the windows were open. Indigo vats are sensitive to drafts and warmth in ways you will only notice once you have the numbers side by side.

The Numbers Worth Recording in the Pot

For an indigo vat, the essentials are the vat type — fructose, henna, zinc-lime or iron — the quantities of indigo, reducing agent and alkali, and the pH, which most fruit vats like around 10 to 11. Add the temperature, ideally between 30°C and 50°C for indigo, how long the vat stood before the first dip, the number of dips, how long each dip lasted, and the oxidation time. Ten to twenty minutes out of the vat before the next dip is typical, but it pays to know what you did rather than what you usually do.

For plant dyes, the pattern is similar. Record the dye material as a percentage of WOF, the volume of water in litres, the temperature curve, how long you held at temperature, and any pH adjustment. A madder bath held at 60°C for an hour behaves quite differently from one pushed to 80°C, and your notes are the only place that distinction survives.

Swatches, Tags and the Discipline of Numbering

Every dye session should produce a physical sample. Cut a scrap of the same fibre you are dyeing, dip it alongside your main piece, and keep it. Tie a luggage tag or a numbered bead to it before it dries, because wet fibre all looks alike.

Give each session a simple running number and use it everywhere: on the tag, on the page, on the photograph. Store swatches in a ring binder, a labelled envelope or a stitched sample book — something you will actually open. Photograph each one in daylight, never under a tungsten bulb, and note the light conditions in the margin. A photograph is a memory aid, not a measurement, so let the physical swatch remain the authority.

Making Friends with Surprises

The most valuable entries are often the ones that went wrong. An iron afterbath that saddened a bright yellow into olive; a vat that was over-reduced and refused to give up its blue; wool that felted because the temperature crept above 40°C. Write these down with the same care as your successes, and add one line about what you would do differently.

Note the small variables too. Did the fibre go in damp or dry? Was the vat stirred or left still? Did you rinse in cold water or warm? These details feel trivial at the time and turn out to be the difference between two apparently identical results.

Reviewing, Refining, Repeating

Set aside an hour every few months to read back through your journal. Patterns appear: your best blues come from slow dips on cool mornings, your greens only work on linen, your reds fade unless you rinse in rainwater. From those patterns you can build a personal palette card — a short list of reliable recipes you trust enough to use on a finished piece of stitching.

That trust is the real reward. A journal lets you stop treating natural dyeing as a lottery and start treating it as a craft you are steadily learning. The surprises keep coming, which is part of the pleasure, but they arrive on a foundation of your own recorded knowledge rather than from nowhere.