Take one sheet of 70lb artists paper (which I buy by the roll), spray with water and then crumble into a ball. Put the ball into a pot of warm tea water and let it cook for about 30 minutes at which point it will have stained brown. Pour out the tea water and let the paper dry. Unless you are me, try and open it up and see it ripping everywhere. One day I will have the patience. Once dry spray with water again and place under a weight to flatten it out even more.
Now you can start drawing in your map. Use the contours of the crumpled paper as a guide for islands, rivers and lakes. Fill it all up. Afterwards add your creatures and boats and other piratey stuff. This one is my test map and I won't post the finished project until after I give it to the kid. The paper has a wonderful texture of crumpley old map, I even tried ironing it to flatten it out since it just wasn't getting there. I haven't decided if the finished map will be ironed or not...
In this one I drew the islands before I stained it with tea, you can see some sharpie bleed in a few places and it made the lines a bit fuzzy. It could be an interesting feature to an old map though...
This one kind of disintigrated in a few spots which may make the drawing hard. I'd iron it for sure first.
I keep adding to this! I'm going to use niece and nephew names for the places on the map and there's going to be a Duct Tape Island somewhere with maybe Adam and Jamie's duct tape boat in the water.