In my eagerness to post I forgot to add the last photo. Here it is:
On both photo's you'll see that the one piece of fabric grabbed the dye more. The darker pieces. Those were the muslin pieces. The other is white pimatex cotton. I did pre-wash the fabric in Synthrapol. This is a specially formulated soap that is natural and won't leave residue in the fabric. Ivory works in the same way. Synthrapol you have to buy at places like Dharma Trading Company,
Dharma has wonderful tutorials in both their paper catalog and their website.
The Procion dyes can be purchased from Dharma or Pro Chemical & Dye, https://www.prochemical.com
Both of these companies are wonderful to work with. Very eager to answer questions.