what this lines?

[Hamedss]

Yesterday I was trying to create something like a semi-transparent curtain that overlaps itself and I ran into this problem. These lines appear between shapes when I reduce the alpha value in the fill color. I have to say that using opacity in the layer settings cannot create overlap in a vector.

[slowtiger]

I suggest to not place the separation there, just to avoid this problem.

[hayasidist]

That's a reasonable workaround - but two abutting shapes shouldn't (IMO) create that sort of artefact. Issue reported.

[slowtiger]

Of course it shouldn't. But lots of stuff happens anyway, in any software, so I've learned the hard way not to waste too much time to make the software behave perfectly (it never does, and it's not my job anyway). Instead I know from experience where problems are likely to occur (especially when more than one program is involved), and supposedly seamless borders are a common risk. Thus I recommend to place your borders/seams where any rendering mistakes are not visible.

[Hamedss]

I think shapes overlapping one pixel. So how do I make that Tiger if there is no separation the shape can not overlap. Any better suggestions?