This article is based on an idea for making sand dunes from 1mm card which was sent to us by Antti Lusila (SeanKhan on the forum).
The first step is to cut two crescent-shapes from thin (1mm) cardboard. Antti used the card from a pizza box for his. He suggest that if you don't have a feel for this kind of stuff you might need to do it more than once before you get it right. We're inclined to agree, but it'll be worth the effort because after you've figured it out for the first one, you can take it apart and use the pieces as templates to make lots of them.
The crescents should be taped together with masking tape such that the front piece is convex and the smaller back piece is concave. You'll then need create a support piece to help the dune keep its shape. Cut the piece so it will match the shape you want for the ridge of the dune and tape it into place.
Now put the dune on the table. Unless you were really lucky with your crescent shapes, you'll find that you need to do some trimming before it makes good contact with the table. The one in the photo needs a bit trimming from the center of the concave crescent.
Next, it needs a base. If you're playing something like Warhammer you can just place the piece on top of a sheet of 1mm card, draw around it and cut it out. However, Antti uses a game system played on squares and it's important to know which squares a terrain piece occupies. Antti therefore used a piece of thin paper, thin enough that he could see the squares of his battlemat through it, and drew the outline of his dune on that. He then placed his tracing on his battlemat to see how many squares it covered, traced around them, and used it to create a 'squared-off' base from card.
That's your 'template' finished. Now you need to take it apart and use it to make duplicates!
Antti finishes his dunes by coating them with a mixture of filler, PVA and paint, with a sprinkling of fine sand applied before the filler mixture has dried.
While writing this article it has occurred to us that a crescent is an intersection between two circles. If we knew the diameters of the two circles, and the distance apart of their centres, we could draw them with and a pair of compasses and a ruler.
Alas Antti's templates are no longer available for us to measure but if anyone else who tries this is able to supply measurements, and of course there will be lots of crescent pairs that will work, we can publish them here for the benefit of others.