FAA Aviation Maintenance Technician Handbook - Airframe on pinking edges of patches

The pinking provides greater surface area for adhesion of the edges and

a smoother transition into the fabric covering. Pinked edge—an edge which has been cut by machine

or special pinking shears in a continuous series of Vs to prevent raveling. 

What Poly-Fiber says about patches and pinked edges:

Should I use straight scissors or pinking shears to cut the patch?
>Use pinking shears.

A&P Mechanic's handbook about pinked edges on patches:

The edges are pinked to provide better adhesion.

Need Manuals? 

Check out the links below!

Gulfstream Model GA-7 Cougar Pilot's Operating Handbook 1978 $29.95 Gulfstream GA-7 POH 1978 $29.95

KAP 100/KAP 150/KFC 150 Gulfstream Aerospace AG-5B Flight Control System Installation Manual 006-00734-0000 1993 $29.95 KAP AG-5B IM 1993  $29.95

Gulfstream Aerospace AA-5 Traveler, AA-5A Cheetah, AA-5B Tiger Maintenance Manual $29.95 AA-5 AA-5A AA-5B $29.95

Gulfstream AA-1B Trainer & Tr2 Owner's Manual 1979 $13.95 AA-1B Trainer & Tr2 $13.95