PurpurhausTinturaria / Porto

Natural dye works / Porto / since 1954

Fourteen dipsto the bottom.

Plants, insects and iron. No synthetic correction, no boiling, and a published recipe for every colour that has ever left this building.

See the ladder
A row of open dye vats in a whitewashed dye house holding deep purple liquid, skeins hanging above
Four vats, one dyestuff. The steam is the only thing here that is not measured.

One skein, fourteen times

The same wool, the same cochineal vat, dipped again and again. The mordant changes at the eighth, which is why the second rank turns towards plum instead of getting darker red.

1Alum
2Alum
3Alum
4Alum
5Alum
6Alum
7Alum
8Iron
9Iron
10Iron
11Iron
12Iron
13Iron
14Iron

A natural dye is not a colour you choose. It is a colour you arrive at, from a particular insect, in a particular water, at a temperature you hold for six hours, and the honest thing to do with the result is to number it and sell it as itself.

Purpurhaus has dyed on the Rua de Miragaia since 1954. Six of us, four vats, a drying loft, and a water supply we have had analysed every year since 1971 because the water is half the recipe.

We are not a natural alternative to industrial dyeing. We are a slower, more expensive and less repeatable process that produces colours industry cannot make, and that is the entire offer.

Five steps

Two days of work and a fortnight of hanging still. The hanging is not waiting; it is part of it.

  1. 01

    Scour

    Two hours in soda ash at a rolling simmer. Grease left in the fibre is the reason most dyeing goes patchy2 h
  2. 02

    Mordant

    Alum for the clear side of the range, iron for the sad side. The mordant, not the dye, decides what colour you get4 h
  3. 03

    Build the vat

    Cochineal, madder or logwood, brought up slowly and never boiled, because boiling takes the red out of everything6 h
  4. 04

    Dip

    Twenty minutes in, twenty minutes out in the air. The air is where the colour actually happens× 14
  5. 05

    Wash and dry

    Rinsed until the water runs clear, then a fortnight on the rack out of direct sun14 days
Skeins of freshly dyed purple yarn hanging on a wooden drying rack in daylight
The loft. Out of direct sun, for two weeks, and no shortcut exists.
Small heaps of dry dye pigment on a stone bench, seen from above
Ground and weighed. From here on, everything is arithmetic.

Three refusals

Each one makes the work less repeatable, which is the point rather than the cost.

A single thick skein of deep purple dyed yarn

I

Every recipe is published

Weights, temperatures, times and water. A recipe kept secret dies with the dyer, and this trade has lost more that way than it has to synthetics.

A glass jar of dry purple dye pigment with a cork stopper

II

Nothing is corrected

No synthetic top-up to hit a target, ever. If a batch comes out two dips lighter than the last it is sold as what it is, with its own number on the band.

A long wooden dye paddle stained deep purple at one end

III

The vat is never boiled

Eighty-two degrees, held. Above that the reds go brown and there is no recovering them, which is one of very few things in this building that is genuinely irreversible.

Ten dyestuffs

Everything in the store room. The mordant column is doing most of the work in this table.

  1. AlumCochinealDactylopius coccusInsect, Canary IslandsCrimson to rose
  2. IronCochinealDactylopius coccusInsect, Canary IslandsPlum to aubergine
  3. AlumMadderRubia tinctorumRoot, grown in AlentejoBrick to orange-red
  4. AlumLogwoodHaematoxylum campechianumHeartwood, importedViolet to purple
  5. IronLogwoodHaematoxylum campechianumHeartwood, importedNear-black
  6. AlumWeldReseda luteolaWhole plant, grown hereClear yellow
  7. NoneWoadIsatis tinctoriaLeaf, fermented vatBlue, by oxidation
  8. NoneWalnutJuglans regiaHull, gatheredWarm brown
  9. IronOak gallQuercus infectoriaGall, importedGrey to black
  10. AlumOnionAllium cepaSkin, from the marketOchre

Anyone can match a colour. The difficult thing is admitting, in writing, that you did not.

Idalina Freire, dyer

Batches, numbered

Every band carries its batch number. When a batch is gone, that colour is gone with it.

  1. PH-214Cochineal on wool14 dips, iron4.2 kgSold out
  2. PH-211Logwood on silk9 dips, alum1.8 kg600 g left
  3. PH-208Madder on linen6 dips, alum6.0 kg2.1 kg left
  4. PH-204Woad on woolFermented vat3.4 kgSold out
  5. PH-199Cochineal on wool7 dips, alum5.1 kg900 g left
  6. PH-193Oak gall on linen4 dips, iron2.7 kgSold out
  7. PH-188Weld over woad3 + 5 dips1.2 kg400 g left
  8. PH-181Walnut on wool5 dips, none8.8 kgSold out

Buying and learning

By the skein
100 g skeins from the current batch, at the door and by post.
By the metre
Linen and silk dyed to a batch, cut from the piece. Twelve metre minimum.
Commission
Your fibre, our vat. Send a sample first; some wool simply will not take.
Teaching
Four people at a time, three days, twice a year. It is mostly washing.

The dye house

+351 22 000 88 00

Rua de Miragaia 88, 4050 Porto. The recipe book is a PDF, it is free, and it is the only thing we send out the same day.

Monday
Vats down
Tuesday
09 – 17
Wednesday
09 – 17
Thursday
09 – 17
Friday
09 – 15
Saturday
By arrangement
Sunday
Shut

An indigo vat is fed on Monday and left alone; anything dipped that day comes out the colour of an apology.