I cut up a silk top bought cheaply from an op shop to yield two short sleeves and a front and a back. They'd been washed but that's all. No pre-treatment whatever. I ironed each of the sleeves then dampened them. Each was then rolled on the cross around a length of red acrylic yarn (salvaged from unwanted scrap at my local arts centre, Craft House in Menora) and tied tightly into a "doughnut".
Each doughnut was simmered in the pomegranate solution for 30 minutes. The heat was switched off. After 30 more minutes, one of the doughnut sleeves was put into a S/S bowl with half a cup of copper solution made by marinating a copper bangle in a 50:50 solution of white vinegar and water for several months. The other sleeve doughnut was left to cool in the original pomegranate solution.
Wet silk rolled around acrylic yarn
Tied in a doughnut
Sleeve 2 Soaked in copper bath after dyeing in pomegranate
Results: the copper soaked sleeve had stronger markings and a darker colour that the sleeve which had been simmered in the pomegranate solution only.