Rendering of non-rectangular outlines

[cofactr-mh]

Is there a way to get the area outside of the board outline to show as black, in the same way that drill holes do, instead of showing as the FR-4 background color? Currently, it seems to render the outline as a line but otherwise ignore it

[lucasrevvo]

The method I use is to get an inverted black image of the board outline, then use PIL to mask the rest of the render with it to make the area outside the curved outline black.