Ok, I've been reviewing all of the scratchboard work and I have a queries.
Zilpa, you made a comment about coloured inks that can be used to add colour. I've found some acrylic inks, and some acid inks. Would one of these be suitable? The fellow at the art shop wasn't really sure, apparently they don't get a lot of scratchboard users in this area.

Ach!! Just got a call and have to go. Will continue with this later. Thanks in advance for any info!