With tongue hanging out for concentration I eventually managed to burn the design into the wood. I did find it a bit off putting when you hit a knot in the wood and you 'skipped' somewhere that you didn't want to be. The tool did get a bit too hot and you had to switch it off every now and then.
I coloured them using Promarkers then gave them about five coats of a water based varnish.
I intend to put photographs on the other side eventually.