quick pro tip I can offer is if you want the engraving to pop is take a color nail polish you like(I used black) and apply gently over the emblems you want to stand out. Let sit for a short bit(about a min). Then use a non acetone nail polish remover and a cotton ball to gently wipe it down till the outside is clean. Let dry for 10 min and reapply. It will take a few rounds to get the effect you want but I think it gives it a nice finishing touch that really makes it look nice.
Thanks. I found a FDE ish color that matched the Coyote tan perfect. I hate doing M9's though as they have sooooo many parts to do if you break it all the way down to coat like I do. Glocks are so easy.