There are 9 boards here making an area about 3' by 5'. The finished board will be 12 sections measuring 4' square (or other combinations). The three that aren't here have more advanced cobbling on and were used for demo games of Systemmech at Steampunks In Space recently:
The cobbles start off as 4mm Depron foam sheet, glued to the smooth side of the metal shelf with copydex. Then I mark a 25mm square grid on the board, keeping the cobbles to squares means I can use the boards for Heroquest, AHQ, Warhammer Quest etc. Hopefully when the Twisting Catacombs scenery finally arrives I'll have a lovely big dungeon to keep it in!
The cobbles are drawn in with a ballpoint pen. Then a couple of layers of PVA are applied to protect the foam, followed by a black spray undercoat and successive drybrushing. I'm currently clocking in at 2 hours per board drawing cobbles, so it'll be a while before this side is finished!
Now, the other side... the fun, swampy side for the Marsh Demons! These metal shelves are about 20mm deep formed of aluminium sheet bent around at the edges, leaving a cavity underneath. This cavity I have been using to sink marshy pools by building up inside the shelves with Styrofoam blocks sanded to the same depth as the shelf. Using a hotwire foam carver and rough sandpaper I then dug out some hollows for the pools, cut a grass-effect mat to the size of the shelves and glued it over the top of the boards with copydex.
The decoration on the boards to break up the even green of the mat is a combination of scenic leaves, lichen, static grass builders' sand, cat litter, bristles from an old paintbrush, ears of corn, tea and branches from an artificial Christmas tree. The lichen I've glued mainly around the edges of the pools and have then glued static grass onto it to give it a thorny, gorse look.
The corn, bristles and Christmas tree needles make grasses for the pools, I've had to keep them short because the boards have to lie flat when turned upside down to use the cobbled side. There are a few animals dotted around the board, like this thrush opening a snail on a rock. There's also a squirrel, an owl and a hedgehog, all from the Oakbound Studio Woods Accessories pack.
Once the decoration was done I used a polyurethane yacht varnish to paint in the areas where the swampy pools will be. I'm using polyester clear resin to make the pools and don't want the resin soaking through the mat and eating away the polystyrene. The polyurethane varnish helps hold together the lichen, cat litter etc. and also makes good wet areas of ground by just painting it into the mat. It's high gloss so I've also used it over dappled green and blue on the cobbled side to create a nice river effect. It takes about 16 hours to dry.
The polyester resin is much cheaper than other artificial water effects, and cures in about 5 hours which is far quicker than any clear epoxy resins I've used in the past. There doesn't seem to be much shrinkage, but I am only pouring pools about 10mm deep. It is more viscous than the epoxies I've used previously, which is good in this case as it helps protect against seepage. It does mean, however, that I've needed to 'tease' the edges into the mat with a mixing stick to prevent domed edges.
I experimented with a couple of pools leaving the metal shelf exposed at the bottom to give the high-reflective look often seen in pictures of marshes. These pools I imagine are much deeper and have been walled around in stone by the inhabitants of the marsh in an attempt to create reliable reservoirs. I'm pleased with the effect of these pools, although the polyester resin did an odd thing. When I poured into the pools the first time the resin ended up with an almost choppy looking lumpy surface. I can only think it reacted in some odd way. Pouring a second layer over the top smoothed the pools out, and has left an interesting mottled effect.
Now, back to cobbles! Oh, and the edges of the boards will be a bit more blended together with the help of some extra static grass!