Elephant Problem

[IQChallenged]

I want to make some one piece jigsaw puzzles that are less than perfect fit. It will make it easier to get the pieces to go in. I want to cut the pocket 1/16th bigger than the piece. I could accomplish this by telling SheetCam that I'm using a 1/8" bit when I'm actually using a 1/4" bit. But I like to think I could order this procedure in Mach. I think I'd be less likely (over the years to come) to get confused. I can draw the elephant (or whatever) in SketchUp and then use the offset function of that program to create an image that is 1/16th bigger. The problem with that is that I have to carefully go at the drawing with the eraser tool to get rid of the inside image before exporting it to SheetCam. Is there some way I could take my elephant (in its actual size) to SheetCam as I usually do, and then give Mach a command to cut it with the 1/16" offset. I stupidly thought I could just bump the X and Y up to 103% (or whatever) to accomplish this. But, of course, that does not work. Thanks for any help.

Picture below shows elephant enlarged with offset tool (in SketchUp) and inside image being erased.