Well, I had done loads more printing and laid out some of my circles with the strips, was pretty happy with how it looked, got ready to take a photo to post here and new kitten rolled straight over the whole lot. So no pictures.
Instead here's a quick summary of what I've used for the printing. I was swayed in the direction of Liquitex by a post on Julie's blog, though I've ordered a couple of ink pads recommended by other people to try out too.
As I reckoned I would only want a small amount of each colour I chose to buy the inks, which come with a dropper, rather than pots of acrylic and I'm glad I did. To mix enough colour for one strip I only need three or four drops of ink (depending a bit on how long it takes me to get a colour I'm happy with) and the same number of drops of the fabric medium.
I really like this stuff - the colours are strong, and the fabric medium works beautifully. I did a tiny sample, on white fabric, not pre-washed. (I'll add a picture when I find it!) The following day I stuck it under the hot tap in the kitchen and rubbed like billy-o. Not even the tiniest smear; it stayed just the same and since my quilts mostly have wool wadding that's about the roughest treatment it needs to stand up to.
I had ordered some (cheap) blank ink pads but they were rubbish, so I ended up mixing on a plastic lid and then just using a quick wipe with a paint brush to put the colour on the stamps. Worked fine.
So now I've done a big pile of colour definitions - and had a whole other load of fun looking through Webster's and choosing them.
Next step will be to reclaim my floor!