Total Pageviews

Friday, 5 August 2016

Dyeing Cotton

This year during the Tour de Fleece I decided to spin some of my home grown cotton. As our team demands that we dye our fibres/yarns as well, I chose the white.  I really don't want to overdye the green as I like the colour as it is.  I carded up a batch of punis and got to work.

I won't bore you with lots of photos of the bobbin filling, but this is where I decided I didn't have time to spin any more and still get it dyed.  So I skeined it and threw it in a pan of soapy water to clean it.

Cotton normally contains a lot of dirt (I know, it looks pretty clean in the photo above) and wax.  I'm not sure if the wax is a result of commercial growing, or if it's produced naturally, but my cotton needed to be clean before I could dye it.  I boiled it for a couple of hours, then changed the water and repeated the whole process 3 times - 4 boilings in all.  This is what my pan looked like after the first boil :-

It took a lot of scrubbing to get that clean.  Then after the subsequent boilings it looked just as bad!  The water was just a dirty yellow colour, nothing dramatic.  Anyway, I ended up with a fairly clean (I hope!) skein.

Next step was mordanting.  Cotton and other cellulose fibres need a different approach from wool and protein fibres when it comes to mordanting.  I found instructions on the internet which used alum, tannic acid, and soda ash.  Previously I'd read that these had to be applied in separate stages, but the instructions I decided to follow did it all in one pot.  All went well with heating the skein in the mordant bath, but the next morning when I opened the pan after it had cooled, I was rather shocked to find this :-

Not a very good photo, but basically all the powders (which dissolved nicely when I put them in the pan of water) had settled on top of the skein of cotton.  The black bits are holes in the powdery scum.  I was a bit worried that it wouldn't rinse off, but thankfully the skein came out nice and clean and ready for the dye pot.

I decided on yellow for the colour and picked quite a lot (300g) of weld that had self-seeded in the garden.

I chopped it all up and cooked it in hot water.  I kept this at a simmering level (not boiling) because I'm always afraid that boiling will spoil the colour.  I left the dye stuff in the water when I added the skein of cotton hoping to get a bit more colour that way.  The result was a pale yellow - interesting, but pale.  I can only surmise that cotton doesn't take colour quite as well as wool and protein fibres because when I've dyed with weld in the past it's been a much deeper and more vibrant yellow.

I wasn't sure whether to ply this or not, so at the moment it's still a single.  I think I may eventually ply it  as, although it relaxed quite a bit during mordanting and dyeing, it still has quite a lot of twist.

No comments:

Post a Comment