contender said:
Most grip makers make their own jigs & such if doing a lot of similar g/f's. Others,, will get a worn g/f of a shape they make,, & use it as a pattern. And the truly detailed & top makers will fit the g/f on the customer's gun.
I have never seen a source for handgun grip patterns etc. commercially.
I make my own grips to fit my hands & my frames. (When I have time.)
As for myself, neither have I seen any patterns available commercially either, and I doubt we ever will.
Most all aftermarket grips are either molded or CNC carved on computer operated machines.
The panels that I've made for all of the Ruger Mark series of grip frame designs have been one-of-a-kind panels, for the A54, A100, Mark II, III, 22/45 and now getting involved with the Mark IV style.
When dealing with a "flat-sided" grip frame involved with the Ruger Mark pistols, there's not too much actual fitting involved, they just need to be flat on the inside faces.
Concerning the Ruger Mark II, III and now the Mark IV variety, there is a bit of inletting involved with the inside faces of the panels involved. That requires a "hard" pattern with the use of an adapted Dremel moto-tool whereby I made a sorta mini-router from:
As for the outside shaping, hole locations, medallion location and hand-cut checkering, these panels are one-of-a-kind and made from the best walnut I can locate: