Every time I have a dyeing day, I include muslin, otherwise known as scrim, in each dye pot. The muslin I use is very open weave and is not the same as the muslin in baby wraps. It is usually white, 90cm wide and comes on a smaller than average bolt. The packet, from the kitchen shops, usually contains a white fabric, 5 metres in length and may be wider than 90cm. This muslin is what you are after and it is used to strain stocks and sauces, wrap puddings, filter wine and press yoghurt.
I fact I have a bag in which I keep textiles to be dyed and it lives with my dyeing equipment. Otherwise I would have to hunt for them and I probably would not be bothered. This bag may include viscose scarves, silk fabric and thread, ugly fabric, fabric to be over dyed, lace, dollies, white skeins of yarn, pfd fabric, cotton covered rope, tassels, wooden beads or buttons, watercolour paper. Just about anything that has a natural base other than wool. Wool requires different dyes to Procion or Drimerene K. Not everything in the bag will be dyed on the next dyeing day but they are all together. Great to pop into a dye bath when there is space.
Getting back to the muslin, I buy a few metres at a time and cut it into 25 cm or 50 cm pieces across the width of the fabric. These then go into a net lingerie bag and I pop the bag into the washing machine with my next load of whites. The lingerie bag is essential as the muslin frays and would become entangled with itself and anything else it comes in contact with. Once dry it goes into my bag of textiles waiting to be dyed.
Some of it I sell but most I keep for my own use. Jan Beaney and Jean Littlejohn include dyed muslin (it’s called scrim in the UK) in most of their works. Here is a link to a free project by Jean Littlejohn
There are many other textile and mixed media artists who also use it. Lynette Collis has on her blog an excellent overview of it’s uses. http://lynettecollis.blogspot.com.au/2013/03/ideas-for-using-scrim.html
Or just do a search for “scrim textile art”. Also look at Karen Ruane, she does amazing embroidery and uses it undyed.
Some of these have been dyed twice. I dye a second time if I do not like the colour, too much white, would like a more mottled effect or on a whim. The grey one is the result of mistakenly adding black instead of violet. I quickly tipped out the solution and rinsed in clean water. Then I made another dye bath containing soda ash, salt and the violet dye solution. It has sort of worked. Into the violet dye bath also went the an aqua, a blue and a red piece that had too much white still showing. A bit of serendipity!