Half Inch Grids Work for Roll20, But Not IRL

So in my free time between (and during) classes in grad school, I thought of making accessories for a Dungeons & Dragons game.

Granted with some foresight there are other ways of making such a thing more efficiently; It's a 18"x24" board with 1/2in squares engraved 0.22 inches apart. The space inbetween correlates with the thickness of the plywood I was using.

Figurines would look best on 1 inch squares. And I could have used 1/8th balsa for the wall pieces. It would also save more wood by cutting female parts into the board and placing male parts on the walls.