How to wash or scour fabric for eco-printing and natural dyeing

Before eco-printing or natural dyeing, it is a good idea to wash the fabric first. New fabric is often coated in waxes, oils and pectic substances that will inhibit the take up of dye. And even secondhand fabric can require pre-washing, for reasons that we will explore. Here I’ll go through a lazy method, a compromise method and a more thorough method.

The lazy dyer’s method – do nothing

The simplest method is to use old clothing or fabric that you know has been washed lots of time. Old white clothing from your wardrobe, secondhand clothing or old bedsheets are all suitable. The absolute simplest approach is to take these and use them as is, trusting that they have already been pre-washed.

The pros of the lazy dyer’s method is that you don’t have to do anything! Just take some fabric and get started.

The cons of this method is that sometimes there are pitfalls. Quite literally in fact, because the armpit of tops are sometimes stained with sweat or deodorant that appear invisible until you dye it. There’s nothing worse than unwrapping a beautiful eco-print …

… only to discover staining has appeared under the armpits!

This is the most common problem, but sometimes there are stains or oil marks on other areas of the fabric that aren’t obvious until you dye it. And of course sometimes clothing bought second hand is actually brand new and never washed. I used to never wash or scour second hand clothing before eco-printing and sometimes I would get great results and sometimes I would get terrible results, from the same set of leaves and mordant and cooking method. I puzzled over it for a long time before finally realising that the washing (or lack of it) was the variable factor.

So to avoid potential disappointment, I recommend washing all fabric before you dye it. This can be done in a simple way, or more rigorously through scouring. Let’s explore both options.

The compromise method – simple washing

If you want to pre-wash your fabric, but still keep things simple, I suggest putting your fabric in the washing machine on a hot wash with a mild detergent, and do an extra rinse cycle at the end to ensure that there are no traces of soap left in the fabric. If you are using new fabric or clothing, I recommend washing them several times first. You don’t need to do a specific load for them, just add them in anytime you are already doing a hot machine wash. Just avoid using any detergent with whiteners or brighteners – stick to a basic one.

The pros of simple washing are that, well, it is simple! If you’re already doing a load anyway, why not just throw your white clothing in too, especially if it is second hand clothing that you are only washing ‘just in case’.

The cons of simple washing are that sometimes it isn’t thorough enough, especially if you are using new clothing or synthetically dyed clothing that you want to eco-print over.

The thorough method – scouring

When using old clothes, this simple method of washing is enough. But if you are using new fabric and want to wash it more thoroughly, you can try scouring your fabric. Scouring is a special type of deep washing used to prepare fabric for natural dyeing.

In the instructions below, you will see that there are several options for scouring ingredients. It’s easiest to start with dishwashing liquid and washing soda as they are available from supermarkets. Synthrapol and Orvus Paste can be bought from specialist cleaning or dye suppliers online, and soda ash is available from hardware or pool stores.

The pros of scouring are that it is the most thorough method so you know for sure that your fabric is now ready for dyeing with.

The cons of scouring is that it requires some special ingredients and is a bit more work to set up and clean up compared to using the washing machine. You’ll also need a very large pot if you are scouring a lot of fabric.

Scouring steps

Step one: To scour, put your fabric in a large pot and cover with water. Make sure that the fabric can move freely as if it is too crowded the scouring will be uneven.

Step two: For every 250g of cotton, add in:
• 2 teaspoons (10 ml) of dishwashing liquid OR 1 teaspoon (5 ml) of a pH neutral scouring agent such as Synthrapol or Orvus Paste.
• 8 teaspoons of washing soda (40g) OR 4 teaspoons of soda ash (20 g).

Step three: Simmer for about 1 hour. The water will turn a yellow brown colour as the waxes and oils are removed from the fabric.

Step four: Let the pot cool down and then rinse the fabric well in warm water.
This method can be used for any cellulose (plant based) fibres but is not suitable for silk or wool.

Once your fabric is washed

After washing your fabric, or even if you are going with the lazy dyer’s method and doing nothing, you still need to prepare your fabric with a mordant or binder. There are endless ways to do this depending on your style of dyeing and the results you want to get. If you want some help getting started, I explore iron mordants in my Gum Leaf Alchemy ebook and Soy Milk Binder in this one.