First Find a local food shop that has vacuum packing machine. The vac will compress the bread without weakening the fibre's as the case would be if you pressed bread the normal way.
Cut the crust of the bread and put two slices into a vac bag on the highest vac setting. I buy Asda
square thick and medium bread and do one loaf of each at the same time. When you get home get a square bait tin and empty the contents of one of the cake colouring pots you buy at the supermarket usualy 40 p each. I use yellow first, put one slice in at a time and leave for about 30 seconds then take out and rest on some kitchen roll, I do this to 6 thick and 6 medium slices top up with colouring if needed. I then dab then dry and put each slice in a bag on its own and freeze them to bring out as and when I need them. I then add pink colouring to what is left of the yellow and this gives you a good red colour, repeat again 6 thick 6 medeum slices. I then add black colouring as this gives a dark brown colour. I also add flavours to the colouring