Everyone is doing it. Boiling books.
I gathered some leaves, bunged them into a concertina book, (I used 140lb watercolour paper with high cotton content), clamped it between two ceramic tiles and popped it into a pan of boiling water with a cup of white vinegar and a teaspoon of tannin powder.
The first two books had walnut ink added to the boiling water. This stained the paper and also the unglazed edges of my tiles. The foliage was simply crammed in between the pages.
The next pages had only vinegar and tannin powder but some of the walnut ink may have leaked out of the ceramic tiles. I was more careful with the placement of the leaves, using much less on these pages.
Next step is to try to so something similar using fabric instead of paper? Maybe. I am a bit fed up of cleaning the cooker…….