marking lumber

Possibly a metal numbers stamp. They come in sets for about $20 for a combine number and alphabet set. You could use a letter for the species and then your identifying number. Harbor Freight has a 1/4” set for $15 and a 3/8 set for $22

-- Les B, Oregon

chalk maybe

does crayon melt off?

carve it

Thanks, I will try those suggestions and see if they hold up and which works best.

-- It's not the mistakes you make that matter, it's the mistakes you leave.

Lumber crayons. I use black, white, blue and red for different marking systems I use when building projects. If all you want is to be able to put a number on there, black or blue, and white is all you need to be able to see it on pretty much any species.

I like it better than chalk because it’s less prone to getting rubbed off. And no, it won’t melt off in a kiln.