What is WOF and how do you use it?

If you have opened a book or any instruction about natural dyeing, you will have see the term WOF. So what does that mean and why do I need it?

WOF is short for Weight Of Fibre and that is relating to the dry weight of the fibers or fabrics that you want to dye. Sometimes it will be called WOG, meaning Weight Of Goods.

Any project you want to dye or eco print, should get started by weighing the fabrics, or yarn, or fibers, when they are in a dry state. Note this down on a piece of paper or print dye sheets you use exclusively for this.

You can download the dye sample sheet I use in my own practice.

If you are guessing the amounts of mordants and dyes stuffs, this can result in under-usage, meaning you will not get the results you want. Or in over-usage which is a waste of resources (and therefor money) and possibly polluting. By working with WOF as a reference we can now use resources like mordants and natural dyes in percentages relating to the original weight.

Example: So let's say you are dyeing three pairs of socks. The total WOF is 66 grams. You would note down total WOF 66 gram and WOF 1 pair which is 22 grams.

If I want to mordant all the socks with 15% of alum, the math is now:

66 x 0.15 = 9.9.

To mordant 3 pairs of socks with a total weight of 66 grams, with 15% WOF Alum, you will need 9.9 gram alum.

Now say you want to mordant one pair of socks with 15% WOF alum, and two pairs of socks with 5% WOF copper, and then dye all three pairs together with 50% WOF weld.

The math is now:

22gr x 0.15= 3.3 gram alum for 1 pair of socks.

44gr x 0.05= 2.2 gram copper for the other 2 pairs of socks.

To dye all three pairs of socks together I need 66gr x 0.50= 33 grams of weld powder.