Aye, the leather need to be vegetable tanned - not modern chromed. Modern chemical finishes protect the leather from scuffing, marking and damage, which is great - unless you want to mark a design on it. Once you have the right leather you need to moisten it. Rub it with a damp sponge on the rough side and then on the smooth side. Wait until it returns to it's natural colour and the moisture should have moved through the leather. Then it should be possible to "draw" on the leather with a blunt stylus and leave the marks.