Well, in the last couple days I've done the following:
Firstly, I tested four different versions of coloring the base and settled on sand as the best way to get some depth and match the bases on my miniatures. This meant lots of glue and sand.
The basic procedure was to slather glue in randomish patterns on about a quarter of a board, deluge it with sand, wait a few minutes, pour off the sand onto some newspaper, pour the sand from the newspaper back into the old salsa jar I was using to store it, then repeat.
I say randomish patterns because where there were cracks on the ground I tried to extend them into the sand a ways to get some jaggedy patterns and hopefully break things up a little.
I waited for a day to make sure the glue had set, then gave it a loose brushing to get rid of some of the denser clumps. Then I mixed up about a 2:1 ratio of PVA glue and water in an ice-cream bucket and began the laborious process of going over all the sand again with a layer of glue. It took about 250-300 mL of glue all up, with it coming down to quite literally about a teaspoon of glue left at the end. Phew! Otherwise it would've been a trip to the shops.
Unfortunately, the sand I used in the first part of the process (last time) I hadn't watered down the glue and as a result those bits are shinier and less bumpy because of the smoothed glue on them. You can see then quite clearly when the flash is on. They'll always be not quite as good as the rest, but hopefully once it's all grey it might not be quite so obvious.
I had to leave that for a night as well, just to make sure the glue all set well. The goal is that with the two lots of glue, the three layers of paint and a final matt sealant finish it'll hold together and not drop sand anywhere!
Today was a good full day, fortunately plenty of paint drying time makes for plenty of rest breaks.
This morning I sprayed them all black using some black spray paint I got from Bunnings, far cheaper than the Games Workshop brand, but not as good quality. For this job, who cares! It just has to undercoat well!
I left them from about 9:30 in the morning until about 2pm to dry off outside. Then I mixed up a tub with some cheap black, grey and white paint (also from Bunnings) so that I had a nice big tub of greyish paint. As it dried it went a little blue-black-grey but it'll be highlighted anyway and the whole tub of paint cost next to nothing.
To apply it I used a sponge and blotted my way over everything. It took a while, but I think it was faster than using a brush and had the advantage of being imperfect for a hopefully more natural look.
So there you can see one coat of the dark grey. You might be able to see the cracks leading through the sand a bit more clearly. The big black areas will be one of two things. In places it looks like the surface has cracked to reveal an ancient pathway or something. I'll be painting those big flagstones a blue-grey colour, hopefully contrasting enough with the more white-grey colour of the sand.
The other black areas are the pits that I will attempt to colour as though they were lava filled. With the bluish flagstones and the yellow lava it should add just a few touches of colour to break up the monotony.
Here's a close-up at this stage.
Next phase was a highlight drybrushing of Codex Grey. Even with the huge area to do I wanted to use the Games Workshop color to match what my minis used. With some Jo Sonja acrylic thinner and a full pot and a half of Codex grey the board was drybrushed and sponged.
The technique was pretty simple. I used a sponge again and lightly brushed it back and forth over the sand to highlight it, then sponged it up and down on the bits with no sand, like the edges, gaps and cliff bits.
This shot compares two tiles, the top one has the Codex drybrush the bottom just the first grey sponging. Hopefully you can see the difference even with the dodgy photography!
And here's the whole board with the Codex coat.
And to put the fortress to scale (which I undercoated grey).
Anyway, next it'll be a final highlight of Fortress Grey. Still not 100% sure how I'll apply it, don't want too much because it's about the right colour at the moment, really just want little bits of it for the extra "lift" you get from it. And especially along the rocks and boulders near the cliffs. Hopefully I'll get onto that tomorrow, it's all up drying at the moment.
All up it took a little under 2kg of fine sand (about $1 a kilo at the pet store aquarium), a little under 2 cans of spray paint ($7 at bunnings), and about $15-20 worth of paints. Oh, and the $5 bag of sponges, of which I still have several left over for... um... sponging stuff later.