I believe the Rockler jig uses 7/8" increments on stock width to end up with the traditional half pins top & bottom of dovetails & I think many like this jig use this measurement also. Example of sizing would be 2-5/8", 3-1/2", 4-3/8", 5-1/4", 6-1/8", etc to end up with the half pins top & bottom of joint.
The PC jig uses 1" + 1/4" increments for sizing dovetails. The sizing would be 2-1/4", 3-1/4", 4-1/4", 5-1/4", & so on. A 5" opening would have drawer parts ripped to the 4-1/4" size to center the joint with half pins top & bottom. If making boxes just size your parts using these rules for the jig you are using to end up with symmetrical joints. No need to cut material after you machine joint to center dovetails.
Have a nice & safe day!
Last edited by jlord; 07-01-2010 at 04:05 AM.