I have done this - don't remember the colors - just the noise... do your
directions say do it on a block of wood? It cut down on the noise and the
softer surface (than the table top) helped the printing -
I did this a LONG time ago and remember it was quite successful. We used
regular hammers on a sort of thin fabric, not remembering what kind it was.
I remember that we used impatiens, and the reds and pinks came out quite
Word of caution: Don't pound to hard or too long in any one spot, it will
make holes and cuts in the fabric!
I would think rubber mallets would work well instead of metal hammers...or
put down something to absorb the sharper edges...felt maybe? Give it a try
on paper that way and see if that would keep the paper from tearing?
Good luck and let us know how it went.