reports from the final California Gen Con...I've been looking at some new rulesets lately - one which uses a very small playing area (2' x 2'), and one which uses a 1-foot grid for the playing area. Both situations made me wonder about the practicality of building some 1-foot-square terrain tiles.
My initial thought was to use foamboard as the base material, but when I brought this up on the forums, there were plenty of alternative suggestions.
In the end, I decided to follow Cold Steel's advice to use vinyl stick floor tiles. They already come in 1' x 1' sizes so nothing needs to be cut to shape, and I was familiar with the product (from having put a floor in a few years back). Also, the tiles are selling 3-for-$1.00 USD at dollar stores locally.
However, from experience I also knew that vinyl tiles can be a bit brittle - they are tough side-to-side, but the corners can get "snapped" easily. So I decided to stick the tiles down to foam insulation - that would reinforce the corners, and give me the option to go "underground" for lakes and other special terrain.
In my area, the thinnest sheets available are 2" thick (unless I special order).
For my first trial, I stuck a tile down on a foam sheet, and broke out my hot knife to trim it out. Fortunately, the hot knife was hot enough to cut through the foam easily, but not hot enough to melt the tile - so I could cut right down the edge.
I chose to undercut the edges slightly, as it should make it easier to butt the tiles together.
Unfortunately, on the second tile, my hot knife "died." Well, not quite dead, but it kept cycling on and off, and didn't get hot enough to cut the foam evenly.
Guess I'm in the market for a new hot knife... 
To give the tiles a nicer look - and to disguise my ugly cutting job on tile #2 - I decided to paint the sides and bottoms. I picked up an inexpensive can of flat black latex paint at a discount store, and started slopping it on. (I didn't want to use spray paint, as I know some paints react badly to foam insulation.)
The first coat went on streaky, but acted as a "primer" that the next two coats adhered to nicely.
I then decided to paint the top a "ground brown" color that would be a good base for future flocking. However, the brown paint I picked up at the dollar store was just too watery. So when a rare stretch of warm weather hit, I broke out the spray paint and painted it with Krylon Ruddy Brown Primer.
So two basic terrain tiles are done for now, waiting for me to add some "terrain" to them. And they fit together nicely, as you would expect.
