2-inch painted wood "stones". Using the material from the DIY Internet Resources, I obtained two yards of felt-backed vinyl in ivory, a black Sharpie "Fine", a yard stick, pencil, and scissors.
Placing the stones end to end, I made sure the size would be acceptable. The stones are advertised at 2" but are just slightly smaller. So a two inch grid is perfect.
Cutting out the vinyl at 23 inches leaves plenty of room if I wanted to finish the edges. The end lines will be 17 inches apart. I didn't include and perspective compensation as many wood boards do, so my board is exactly square.
Once you have the grid ends marked in pencil, you can draw each grid line with the Sharpie.
That's all I did for my first "giant vinyl board". The next one will be 13x13 for 2" stones. That'd be a total width of about 26 inches.
As I mentioned in the last DIY article: I am not crafty. If I can do this, you can too!