I was experimenting with the letterpress inks to see if they woul blend and yes they will! You have to be a little careful about contaminating across and getting one big midway colour on the plate (1st couple of attempts) but I managed to get 2 colours on - but maybe all that is out wayed by the fact that this background plate just makes your eyes go a bit funny - it seems to move if you look at it too hard.. look away! look away!
colours I used were blue and green, maybe if I'd used more diverse colours it would have been more obvious but as I said I was just playing around and these were the colours I had to hand.
The other thing to note is that the big background plate (left) did not want to go all the way through the machine with a complete piece of card stock - I used a small postcard sized piece in the end... I'd hate to damage anything (lol).