Plant roots, stale urine and rain, oh my!


(Or a fast beginner’s introduction to medieval dyeing)

Ever since I joined the SCA I’ve been plotting to set up to recreate dyes. I’ve done a fair amount of research by now, so I expect there will be a few posts on the subject to follow, I have a lot of plans.    This particular post is designed as a sort of Beginner’s Guide to Dyeing, I’ll be getting into specific methods and recreations as I go along.  So, first things first

– What am I trying to change the colour of?
There are different applications of the techniques described below depending on whether you use animal (eg. wool) or plant derived fibres (linen, for my purposes).  I’m going to focus most of my experiments on wool,  as I’m given to understand that there’s a trick to dyeing linen.   Whatever the material, the trick is to to change the fibres subtly – eg. strip out oils and waxes –  to make the colour particles penetrate the fibre as much as possible.   This is where school science and a knowledge of the PH scale, acids and bases starts to come in handy.   The pretreatment stages are generally known as “scouring” (cleaning) and “mordanting”.

Equipment: You’ll need large stainless steel or enamel saucepans, big enough to allow your wool/fabric lots of room.    As ever, a warning! Never use pots and utensils you use for dyeing in food preparation.  Once they’ve been used for dyeing, stick them in your shed for dyeing purposes only. Also, make sure you work in a well ventilated work space and invest in a face mask.

Remember rainwater is softer than tap water in most places, and doesn’t have chemicals like chlorine added.  It’s by far a better option, so setting out a bucket or rainwater butt would seem sensible for a long project.  If you’re using tap water, let it stand over night before use.

Pre-treating your fibres

Scouring is a word I associate with great hanks of steel wool and lots of elbow grease.  It actually just means a really good wash.  Even commercially bought clean looking wool and linen need this cleaning.   

For wool: (not fleece)  Soak the wool in warm water (between 50 and 60 C, or just hotter than  your hand can stand) with soap for at least 2 hours, but preferably overnight.  Rinse very carefully,  handling wet wool too much will cause it to felt.  Never, ever truly boil wool, even if your recipe says boil.  Again because it causes felting. Wool also hates extreme temperature changes, you guessed it, felting.  Felting is a whole other (also fun) pursuit, but not what you want for this exercise.  Shop bought wool yarn doesn’t need such a long scouring time, but patience will be rewarded take the time when you can afford it.  Avoid acrylic mixes like the plague.

For linen (and cotton):  In the saucepan add Sodium Carbonate (Washing Soda) and soap to hot water – avoid any detergents with colour additives and brighteners, I get the impression plain old soap might be better than washing powder.   Simmer the cloth for again at least 2 hours. If you can double that you get better results.   Washing soda is caustic and increases the alkaline properties of the fibres.  Ammonia can also be used, but the thoughts of the smell puts me right off the idea.   You could of course always use properly medieval stale urine, but I’ve already decided I’ll pass on that though.

The purpose of using a soda or ammonia assistant and increasing the alkalinity is to improve absorption of the mordant, the next stage,  and this helps with colorfastness.  PH 9 or PH 10 is good!  In terms of quantities to use there’s a lot of “throw in some and a dash of”  as there are with most medieval recipes.   I’ll be working these out for each recipe I work on, one by one.

Right, now that everything is squeaky clean we move on to the Mordant.  Mordant  derives from the Latin word mordere, which means to “bite”.   The fibre is “bitten into” by solutions of metallic salts and chemicals to open up the fibres to accept pigment and to act like a binding agent to make it last.   The basic mordants to start out with include
1) alum (Potassium Alum) and Cream of Tartar when mordanting wool and
2) alum and tannic acid – in my case oak galls  when mordanting linen, with an occasional option to use ferrous sulphate (Iron).  

Iron is more often used to alter the end result of the dye – to “sadden” or darken the end colour.    I’ll give quantities and methods for each colour I try in following posts.  Fibres should be allowed to soak in  mordant solutions for 24-48 hours, and storing fibres for a while after mordanting and before dyeing seems to help too, but I want to do a bit more research on that.   Mordanting becomes a science in it’s own right, this is just a basic introduction for now. Other metallic salts can be used to alter colour but that’s another day’s work. 

Given the beginners guide spirit of this post I’m going to stick with colours that are well known as “medieval” (Usually quite a bit older in origin, but definitely used in the medieval period).  These are what I consider a basic palate, and are the ones I’ve chosen to start with.    My plan is to write a post for each dye as I try it and to try different fibres, mordants and assistants to see what happens.

Red – madder and cochineal
Madder dye comes from the roots of the madder plant.  Cochineal comes from beetles.
Blue – Woad – woad doesn’t need a mordant, so this is a good choice for linen. Woad dye comes from the leaves of the plant
Yellow – a very long list indeed, weld being a common one.
Green – more difficult than I first imagined, often a yellow overdyed with a blue, investigating some other options.
Purple – logwood, or, as I discovered earlier today, brazilwood, tannic acid and ferous sulphate 🙂
Brown/coffee– oak gall tannic acid.
Black – oak gall derived tannic acid and ferous sulphate

The dye solutions will all be described as I make them up, but for the purposes of this post I’ll just warn you that you will need big containers for dyebaths and a lot of patience.  Good colours tend to come with time.   A dyebath will yield a little of your primary, strong colour but lots of paler shades – I expect madder red to quickly give way to rose and pink.  I suspect there was a lot of pink, given the small amount of messing about I’ve done so far.

One Comment Add yours

  1. The Middlegate Key says:

    Reblogged this on The Middlegate Key.

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