After this, I decided to try printing onto an acrylic-painted surface. It turns out that it works rather well, but takes quite a bit longer to dry – I suspect I can generalize from that to say that the drying time depends on the absorbency of the paper beneath.
Here is the result, which is now framed and hanging on my kitchen wall. (Mounted in a simple A4 clip frame, with a sheet of neutral-grey acid free paper between it and the mankboard backing.)
I don’t feel I can sell high-days prints, but I’m happy to give prints from this block away to good homes.