P.Bigham, All that I have seen were wrist only, and 8 or 10 lines per inch. They form squares, and it is typically called flat-top checkering. So you don't want to use your vee tools with a lot of "oomph" behind them, lightly does it.
Sometimes the squares will have small circles or dots in the middle, but I made one with silver round-headed nails.
You could probably use a "skip-line" tool as I did - I did one with a 16 lpi, used an 8 skip for that. The 20 lpi, you would use the 10 skip, thus giving you 10 lpi.
Like my customer said, ain't no place for fancy skip-line or basket weave patterns!
Good luck, and let us know how it goes.