Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Where the two Digital Raster Quad sets (topo maps 7.5 Quad) overlap there is a significant thick black line (not a single line but wide and is wider the further south you go on the map). I am looking to remove this line or join the two so the map is not interrupted. The line also goes through the middle of the area I am working. Directions on how to solve this would be greatly appreciated!

enter image description here

share|improve this question
Here is a closer shot… where the two rasters overlap is the black line – Lyloak Sep 9 '12 at 1:38
up vote 3 down vote accepted

This is the "black border" problem. It's what happens when a map image is rotated when reprojecting from one CRS to a different one. Try a Google search for something like "QGIS black border".

You could try this for starters. Load one of the images, right-click on it in the layers panel, select "Properties" and then click the "Transparency" tab. You'll see a group of four icons, click on the one with the arrow and the question mark, then click on the black border. After that, click "OK". The black border should disappear, but so might some of the detail from the map. If the loss of detail is too great then come back.


share|improve this answer

Best way to avoid the black border is to set the projects CRS to that of the raster maps used.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.