I hadn't even thought of this type of project until someone asked me to try it out. 4x6 birch plywood.
Things I learned: Baltic birch ply needs far higher laser power to get a good burn than the hardwood like cherry that I've been using for my wooden notebooks. This card I burned at speed 1000 and full power. On cherry, I use power 150 for a nice dark burn.
Also, I feel like my laser is struggling with accuracy on very small letters. You can't see it here because this text is pretty large, but at small sizes I get some ghosting and fuzziness that I feel like I didn't have before.
Anyway, some testing for me to do, but this recipe card came out nice. I think I'll be making a dozen or so for this person.