Today the baby alpaca came out of the dyepot - and I was a bit surprised to see how different it was to the wool sample I dyed yesterday :-
That one is a really bright, vibrant green (in fact, it looks like I've photo-shopped it, but it's the original photo taken in exactly the same light as the top photo) and I couldn't understand why the baby alpaca was duller. I love both colours, but the ratios of wool to flowers were almost the same in each case. Then I realised what I'd done.
When I dyed the small sample, I used an aluminium or stainless steel pan, I'm not sure just what it is. But when I did the second batch I needed a much bigger pan so used my large enamel one. Enamel is usually good for dyeing because it won't change the colour of the dye. Unfortunately, it's getting a bit old and there are some "dinks" in the enamel where bits are missing. Underneath these patches it's probably a bit rusty, and rust = iron oxide. Iron is a mordant and is often used as an after-bath to alter the colour of dyes. Iron "saddens" the colour, and I think that's what's happened here.
I think I'll have to spray the pan with some enamel paint so it doesn't happen again.
I was just about to throw the rest of the contents of the dyepot onto the compost heap this morning when I realised there was actually quite a lot of colour left in there. I strained the dead flowers out (which were getting a bit pongy) and put some of the liquid into a large plastic bowl. I still had one more skein of baby alpaca which I'd mordanted, so that has gone into the bowl. I'll leave it in there for a few days and see what comes out. If it's a brighter colour it'll just reinforce my theory of the pan being to blame.