When I talk about natural dyeing most people ask if the colours are light fast and washable. The answer is yes if you use the right methods of dyeing and mordants. Mordants are the chemical fixers used to fix the dye to the fibre. Years ago I used to use Tin, Copper, Chrome and Iron until I realised how poisonous they are. Now days I use Alum, natural and harmless. This can restrict the colours that you get so I started making safe alternatives. Soak copper piping in a solution of half vinegar and water for about three weeks until it turns blue. This is a good mordant and you just need to top up the solution as you use it until it no longer turns blue then change the piping.
Treat rusty iron nails in the same way. Be careful as this can be a bit hard on the wool and make it brittle. Best used as a modifier.
Rhubarb leaves simmered for one hour then strained make a mordant and a yellow dye in there are own right. The root of the plant can be used in the same way. This is no hardship, I love Rhubarb.Modifiers are used at the end of the dyeing process to alter the colours by making the solution either acid or alkaline. Citric Acid, Vinegar for acidic solutions and Washing Soda for alkaline are just a few that are available. It is best to use these sparingly as they can damage the fibre, but you don't need much to change the shades in the dye bath.
I like to mordant a lot of wool ready to dye at this time of the year because dye plants are coming thick and fast form now on and time is short. It is a way to make sure I am ready to use the ones I want before they disappear for another year. There are always some I miss, there are just not enough hours in the day to do all I want to do.
