Just thought I would start a thread to share a few of my tips and tricks to working with Inkscape to produce new parts/boards for Fritzing. (please feel free to add your tips and corrections)
Setting up Inkscape.
Set transformation parameters.
Disable “Scale Stroke Width” (makes it easier to change size of holes in rings, etc)
Disable “Scale Rounded Corners in Rectangles” (makes adjusting custom PCB size more consistent)
Enable “Optimized” Store Transformations (should be enabled by default and should prevent some extra transformations from being inserted)
Removing extra transformations inserted by Inkscape.
Option 1) (Works 99% of the time)
Ungoup objects until they are no longer in a group (Ctrl Shift G repeatedly or Extensions/Arrange/Deep Ungroup) and then Re-group (Ctrl G) and rename the group to its original name.
Option 2) (should work but I have not had the best of luck as it has made some unexpected changes but worth a try)
Use Apply-Transformations extension https://github.com/Klowner/inkscape-applytransforms
Repairing Custom PCB with holes. (If Fritzing says your PCB does not have any holes but it should)
Select all board parts while holding shift. (You may need to be in node editing mode not object)
Union all board parts into a single outline (Ctrl +)
Break apart previously unioned board outline (Ctrl Shift K)
Select 2 previously un-unioned paths that should be holes (while holding shift) and union them together (Ctrl +). (You may need to be in node editing mode not object)
Repeat adding hole paths one at a time until all the holes are one object.
Select the board outline and the previously unioned holes while pressing shift and difference them from each other (Ctrl -).
You should now have a Board that Fritzing recognizes as having holes. When you use the board in Fritzing it should tell you that you have 1 hole more than you actually do. (it sees the outer path as a hole plus the actual holes).
Resizing all rings equally in Copper layer.
Resize each copper ring individually taking note of the difference in the size (before +/- after)
Move entire copper group half of the difference in size. If you increased the size move the group negative on X and Y (size difference/2). If you decreased the size move the group positive on X and Y (size difference/2).
When I think of more I will add them.