All the maps are completely hand-drawn with a pencil and a couple of black fineliners. The second image shows a scan of the first image. I corrected a couple of small mistakes, applied the cartoon filter in GIMP and used a grey fill for solid areas.
The Kickstarter project has now passed its first stretch goal. This means all the sheets in the pads will be double-sided, with a 7mm grid on the front and a 3.5mm grid on the back. Here's a link to the project page: