In my previous post on eco printing I wondered whether the faintness of the prints, especially on felt, was due to the fact that the steam couldn’t penetrate the felt very easily when it was rolled up.
So I performed a similar experiment but this time I immersed the bundles in hot water and onion skins and simmered them for an hour. Then I left them to cool overnight and opened them up the next day.
The results were definitely better, particularly on felt.
Oak leaves on cotton mordanted with aluminium acetate (below) gave a lovely clear print, regardless of which mordant was used on the leaves (or even when none was used at all).
Sycamore and rose leaves also printed quite well on cotton, but those dipped in the iron mordant were clearest.
On silk, iron-mordanted sycamore and oak leaves did best, while eucalyptus and rose leaves were pretty similar for all mordants.
Conclusion? It looks as if full immersion rather than steaming is the best way to go, unless I can get a large pressure cooker or find some other way of forcing steam through the fabric more efficiently.