So I know that the grain of the wood on the lid for a box call is supposed to be vertical and that it should run against the grain of the box itself. The Question that I have is on woods like Padauk, Yellowheart and Purpleheart how do you tell which way the grain is??? Maybe I need new glasses or need to clean the ones that I wear in the shop but with the stuff that I have on hand its hard to see which way the grain is running and I have all of the above in 2" thick or better.