The dyes obviously are one of the stars of the show but there are several different types and they don’t all do the same thing. I use acid dyes but to put it in context and set the scene, I’ll whizz through the other types too.
The main categories for the home dyer are acid dyes, food colouring/Kool Aid powder, natural dyes derived from plants, minerals and insects, and Procion MX dyes. These dyes work on protein (animal) fibres or cellulose (plant) fibres, or both. They won’t work on acrylics and if you are hoping to experiment with dyeing some cheap acrylic you have lying around, forget it. The chemicals needed to dye acrylic are nasty and besides acrylic is usually dyed when it’s still gloopy and not yet extruded into yarn.
Each dye category has its pros and cons. Food colouring is obviously non-toxic, so you can use your normal kitchen equipment, but certain colours are harder to achieve or can ‘break’ apart in more acidic conditions. Black is a good example of this, as it can split into its constituent colours (there is no pure black food dye; it is formed out of other colours) and ‘breaking black’ is something that I will cover in a later post.
Natural dyes are something that I would love to explore in the future – you can get some really beautiful shades from these sources and they work on both protein and cellulose fibres. However the natural dye palette, although varied and gorgeous, can lack the brightness and brilliance of ‘chemical’ dye colours.
Procion MX dyes work best on cellulose fibres and their low dyeing temperature has earned them the name ‘fibre reactive’ dyes. They do work on protein too, but you need to change the environment (i.e. you need heat and acid as opposed to cool and soda ash) and they aren’t quite as successful in terms of saturation and colour fastness as acid dyes.
So that brings us neatly to the dyes I use. Here they are:
The reasons why I chose Ashton acid dyes were very simple: I knew that I would be dyeing only protein fibre for the foreseeable future (they don’t work on cellulose) and some of my favourite dyers use them, so I thought I would like the results!
Acid dyes are fairly safe for home use, you just need to watch them when they are in powder form and wear a mask while mixing them. They bond to fibres when acid and heat are introduced and you can get an amazing range of effects.
At first I used distilled vinegar as the fixer for the dyes – it’s fine for in the kitchen, readily available and cheap. But you do need a fair amount of it if you are spending the afternoon dyeing and the smell of hot vinegar lingering around your house is not great after a while,
So I moved on to citric acid, another kitchen-friendly one. Actually I had a load of it hanging around as I had order some for making elderflower cordial last summer and got a 1kg by mistake… If you are soaking yarn for handpainting, you only need about a teaspoon of it for a whole basin of water.
For successful (and repeatable) results, you can test the pH of the acid bath. Universal indicator paper is what you need for the job and I’m using some of my husband’s grandfather’s stash of it:
(They’re a scientific family, you see)
I usually aim for a pH of 4, but others have found that it’s all worked out at around pH 5 too. As with all these things, you have to experiment to get the results you want. At the end of it all, add some bicarbonate of soda to the water before pouring it down the drain to bring it back to a neutral pH.
The other thing to mention is that the effect of dyes is greatly determined by the yarn base that you are using. You can get really different results with the same dye on different bases. This is especially true of natural dyes, but you can certainly see the differences even with acid dyes.
And there you have it: acid dyes in a nutshell.