after using the vectorizing tool I get the following result (picture). Around the cells you can see a small "boundary". This thin line is transparent and annoying. Is it possible to remove these small transparent areas?


  • If you click on that small section does it select the row in which it is in?
    – Ger
    Commented Aug 4, 2015 at 11:42
  • I cannot really hit the small parts. The closer I zoom in I don't see the little sections.
    – Pimpel
    Commented Aug 4, 2015 at 11:44

2 Answers 2


Change the style of the vector and make the border the same colour, possibly a bit thicker too. That should mask it. I'm guessing that it isn't a real gap.


  • How can I change the boarder color and thickness?
    – Pimpel
    Commented Aug 5, 2015 at 7:51
  • Added an image to show where to look. This might help too: docs.qgis.org/2.0/en/docs/training_manual/basic_map/… Commented Aug 5, 2015 at 17:23
  • I tried it but without success. I guess the boarders are transparent...that might be the problem.
    – Pimpel
    Commented Aug 6, 2015 at 14:08
  • @Pimpel did you try changing the colours to be the same? If you make the border transparent it will still show up. Commented Aug 6, 2015 at 19:22
  • Do I have to this manually?
    – Pimpel
    Commented Aug 6, 2015 at 19:59

simmilar problem here ...
and i've tried all the suggestions form above and found some other sources, like http://gisforthought.com/polygon-outlines-in-qgis/ and How to remove tiny polygon outlines in geoserver sld? ... without beeing successful.
so i finally set up a test-polygon-file with a regular structure based on non-overlapping and gap-less squares (see pic. 1 - with identical point coordinates at the corners). displaying these polyogns with white "Simple Fill", outline style: "No Pen", units: "Map Unit" on top of a magenta project-background shows that "small tansparent outline effect" (see pic. 2) . these "gaps" are

  • not a result of the underlaying polygon-data (non-overlapping and gap-less!)
  • scale-independent ... they vary in size but do not vanish completely in any scale
  • are displayed in qgis as well as in print composer outputs (showing differnt dimensions in bothe of them!)
  • and removing these "lines" by setting corresponding border color manually is just a workaround, which isn't really comfortable in particular if you use a lot of graduated symbols layers.

so, acctually i can't provide answers but give some inputs for narrowing down the problem ... but in 2013 that was discussed in the context of "the gamma parameter of the Java antialiasing" - see andrea aime's comment How to remove tiny polygon outlines in geoserver sld?

pic. 1: enter image description here

pic. 2:enter image description here

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