Few people ask me to know how make a project.
I show you my method with Photoshop.
Of course you can start with a picture of part of knife or other. Here is a part of gun.
1 when I make the extern line of my part to engrave, I begin to draw with pencil.
2 When my extern line is finished I scan the picture and I complete the background with black paint with photoshop
3 When is complete, you print this picture and you draw the shadows lines with pencil.
This proceed is for me easier and clean.
Now I hope see your beautiful project ;-)