The Contact Dyeing with Metal Surfaces indeed results in really nice color combinations on the fabric.
This is a silk fabric rolled over a copper pipe with various plant material, simmered for about hour and a half. The bundle was left for 4 to 6 days to cure.
Another silk sample
However, there is always a tricky part in the Contact Dyeing with Metal Surfaces. And it is determination of the curing time. As a slow process Eco Dyeing requires the longer time for the better results. But in this particular case the longer time sometimes equals, along with nice color combinations,
holes eaten in the fabric. Silks and light cottons are especially vulnerable to the metal corrosion impact. Well,at this point I have not yet figured out how to get round the fabric damaging and get the same great color effects.
And a little bit better result: