One of the most frequently asked questions I get is something along the lines of, "How can I dye fabric with natural dyes and get more even colours?"
The truth is that is is very tricky to dye with totally even results; it's a challenge even for experienced dyers. However there are certainly some tricks for getting more uniformity across fabric and garments that you are dyeing.
Keep stirring
Getting even results can be time-intensive and the biggest secret isn't really a secret after all: the fabric just needs lots stirring. You need to keep the fabric moving so the dye doesn't settle into the folds and dye those areas darker.
It's much easier to dye an even colour on smaller pieces of fabric. It's virtually impossible to produce an even colour across an entire bedspread or pair of curtains. In these situations I always suggest using a tie dye technique to create a subtle pattern. Then you can control the pattern, rather than end up with unexpected patchiness.
But even when dyeing smaller pieces of fabric, we can try to do everything perfectly and sometimes the results are slightly patchy for various reasons. Hopefully some of the points in this blog post will help you resolve any patchy dye problems you experience. This is like a brainstorm of all the different things that could happen - and have happened to me at one point. I hope there are a few tips that you can take away to help you.
1. Prewashing fabric
Clean your fabric as well as possible before dyeing to remove the residues of oils from the manufacture. For lightweight fabric, you can probably get away with a thorough machine wash as I describe in my book, but for thicker canvas-type fabric and thicker linens, you may decide you need to "scour" the fabric. Or maybe you will choose to do a very hot machine wash. I tend to dye mostly delicate fabric or clothing and choose to treat it more carefully and don't like the effects of traditional "scouring", but I always thoroughly wash (sometimes more than once) and rinse well.
If you don't prewash your fabric or clothing well, then your dye will most likely attach to the fabric unevenly and look patchy. The dye may wash off easily as it hasn't truly bonded to the fibres, but is sitting on the surface over the top of the residue of oil.
2. Mordanting
If you use the soya milk pretreatment method for "mordanting" your fabric (as per the instructions in my book) remember that the aim is to get a really light coating of soy protein on the fibres and then spin out the excess milk in the washing machine.
When you hang the fabric to dry, it's vital that the milk does not drip down the fabric. These drips will ultimately cause darker streaks of colour when you come to dye the fabric. If you don't have a washing machine to spin out the excess milk, then you might decide to dilute your milk solution even more than I suggest (such as a 10:1 ratio of water:milk) as this will reduce the chance of a patchy milk coating. Keep in mind that you are aiming for several dips in diluted milk.
3. Dyeing Fabric
Strain your dye through fine fabric to remove any left over bits of plants. Any residual pieces of plants could cause marks on the fabric.
Use the largest pot you can find to give the fabric as much space to move around as possible. There isn't an easy way to calculate the perfect dye pot size; my suggestion is to look for the biggest you can possibly find.
The thicker and heavier the fabric, the larger the dye pot you will need.
Before you add your fabric into the dye pot, add in extra water to bring the liquid level up. This gives the fabric more dye to move around in. The aim is to allow the fabric to move as freely as possible. Remember that when you add in extra water, you're not actually diluting the dye. There are still the same amount of dye particles in the pot, they are just more dispersed within the dye bath. It might take a bit longer to dye the fabric a darker shade, but the overall colour is likely to be more even than if you dye in a smaller volume of liquid where the fabric has less space to move freely.
Dampen fabric before putting in the dye pot as this helps the fabric takes up the dye more evenly when it first enters the dye. Wearing gloves, try to squeeze the fabric in your hands as you put it in the dye bath to eliminate pockets of air. Keep squeezing and agitating when the fabric is under the dye level until no more air bubbles rise.
Keep the fabric moving when it first enters the dye bath. Wet fabric can stick together and areas that don't receive the first take-up of dye can end up lighter in colour. It's important to agitate and stir as much as you can.
Keep stirring the fabric in the dye pot for the entire time that it is in there. Don't leave it unattended and forget about it, as the dy