burn tested the laces (there are 3 differently sourced laces), I had a quick ignition, bright flame, a woody smell and an ashy remnant, no beading, which I thought indicated a natural fibre, such as rayon or cotton. As this is elderly lace and was quite costly at the time, this seemed a likely fibre for its composition, so I dyed it using a fibre reactive dye, by the tub dyeing method, using these techniques from Dharma fabrics specific to black.
Note: Soda Ash is called Washing Soda in Australia (sodium carbonate) and I bought mine very inexpensively from the supermarket.
I had several dyes, and chose #300, as it is described as having a blue cast, and the under fabric for the dress is a silvery blue. I now strongly suspect that the netting of the lace is a polyester, and in my opinion, the cast is purple, rather an attractive purple, but definitely not blue.
At the same time, my older daughter threw in a cotton/lycra singlet to tie die.
In the left over dye bath, I soaked some some allegedly Irish Linen placemats that my mother retrieved from a church garage sale in case I might need them.
They were a pastel blue that I find hideous, and I much prefer their new colour. They may end up in a garment, or we may have new placemats.All this dyeing took 3+ hours of activity, and 30 minutes soaking time in dye fixative solution. I enjoyed it, but I don't think I'll be doing it regularly.