The idea is to create module pieces that share similar size characteristics that allow them to fit together.
Originally I tried to make these using cork tiles - but couldn't find any thick enough (I could only find 3mm width ones at Wickes). So I decided to try 6mm MDF instead.
As a result I popped down to B&Q and picked up two 2' x 4' boards with the idea of making 16 12" x 12" blocks. However, the guy cutting them messed up (one set was exactly 12" but the other came out at 11.7" - not ideal for modular terrain!).
He explained that the saw took 3mm off when it cut. We discussed the problem and he suggested buying a huge sheet of MDF (4' x 9') which he'd then work on.
He cut the 16 blocks - and there was still a block of MDF of about 2' x 4' left! The sheet only cost £9.40 (which was just 20p more expensive than a much smaller board and - amazingly - a good £4 cheaper than the original two boards). In effect I got all 16 square boards AND another sheet of 2 x 4 MDF for £4 less than two 2 x 4 boards!?!
I got them home and have started to mark them up. I'm following Matakishi's general guidance to mark them up to cut them into rough halves, thirds and quarters - leaving some rounded edges and some straight.
More to follow!