OK so I may not have explained well what I was speaking of! I have the feeling that what Ken and Leatherman, you were both speaking of is the basic overall shape of the sheath!
I don't have a drawing program so will try to do this on the only medium I have available, pictures from the net!
I realize my groover can be ran from the edge by setting the guide.
So that takes care of the stitch line basically. However what if I have to do some freehand grooving. I would need a line to follow and if your hand is not particularly steady, you will leave the line!!
So the next area that comes to mind is something like this Chuck Burrows knife sheath!
If you look closely at the sheath, just inside of the tack line there are two lines that are parallels to the edge. I am guessing that those lines may have been done with a Swivel knife. A tool that I am still learning to master. Sometimes my lines look good and sometimes not so good. LOL Even the pattern he put in the field on this sheath. I would have to lay it out before using the swivel knife!
So here is another of Chucks sheaths. Now I realize this effect of the diamonds in the field was more than likely done with stamps, in the area around the diamond itself! However I know for myself I would have had to layout the pattern on the face of the sheath, so as not to screw up. Chuck on the other hand may have done it freehand. He had a way of making it look simple, even if it not!
So basically what I am speaking of when I say layout, I am talking of what will appear on the face of a sheath. I have done some pattern layout on the face of a sheath and when I get done I will realize some of my lines still show!!!
So on this kind of layout, (on the face of a sheath) Leatherman are you using the red felt tipped pen?? Something like these made by Sharpie!
I hope I explained myself well enough this time to make sense of what I was referring too!