This slide is engraved in American Scroll with a stippled background to bring out the intricacy of the cuts. The cuts were then inked to really make them pop. Inking is a great idea for stainless guns to bring out the detail work.
This customer only wanted the slide engraved so it was a relatively inexpensive way to add some custom charm to this everyday carry gun.
Take a look at some of my other Walther PPK-S work here and here to get some ideas for your own carry pistol.