Shapes don't meet precisely when using path combine tools.

[Smched]

When combining two filled shape paths (ie, union, difference, intersection and so on), I have found there is often a slight break between the two where the lower layer shows through.

I have tried executing the combine both when the path has a stroke value and when it doesn't with the same results both times.

[prkos (prkos)]

You shouldn't be seeing this if you use Union because the result would be one path.

But if you combine Difference, Intersection and Combine to make shapes one next to the other like in your example due to antialiasing of the object edges you'll see a very thin area of background showing through. The edges of the objects are blurred a bit to make them appear nicer, but the side effect is what you encountered.

[sas (sas-sas)]

I don't think this can be an antialiasing artifact, as the image shows that it's thicker when you zoom in. Antialiasing artifacts remain thin no matter how much you zoom in.

To progress with this bug report, we really need an SVG file that demonstrates the problem.

[prkos (prkos)]

Sorry for the wrong classification the last time, thanx sas for pointing it out.

Im attaching a file and a screenshot where mistakes are even more visible because the gap between the paths varies in width (and on some segments there is no gap because they overlap).

I created an object with rough edges using calligraphy tool with tremor, created a rectangle so they overlap, duplicated the calligraphy object and made Difference with the rectangle.

[sas (sas-sas)]

This is probably a duplicate of bug 168158.

[su_v (suv-lp)]

Linking as duplicate to Bug #168158 “Path Boolean operations are imprecise”
<https://bugs.launchpad.net/inkscape/+bug/168158>

Please add a comment here and revert the duplicate status if you don't agree and think these are different issues.