I never used software to construct fretwork patterns. I just freehand my own, but they are very simple ones for pens that I do. I couldn't freehand a decent sized pattern. Far as I can tell, most people are using GIMP. Seems that it is a freeware program as well. Another popular program is Coyote Stencil. Somehow you scan your image then alter it with the software. Then you use a color fill to test the pattern. The color fill will show you if there is anything loose in your pattern, such as an eye..the eye has to be connected to something, otherwise it would fall out when cut obviously. If there is a fallout section or piece, you then manually repair it by stringing it to the main structure. there are cd's and video tutorials available on the web. Knowing you, and you abilities with software and machinery, I have total confidence you will figure it out.