I'm running ArcMap 10.3 and every time I export a dot density map it "slices" long, horizontal gashes in sections of the dots (see screenshot below). The cuts are never vertical, always horizontal, and it doesn't matter if I export as a PDF or image file like PNG or JPEG.

In the example screenshot, I have a dot density layer representing population data on top of a choropleth map showing demographic indices. The only other layers in my TOC are a shaded relief raster and a freeway/roads line layer.

Right now I'm simply manually exporting the map as a PNG at a resolution of 400 dpi, but the slices also show up at a lower resolution (such as 300 or 250). It's worth noting that the slices still show up even when I export the map using the arcpy.mapping.ExportToPng tool in my script.

Wondering if anyone else has noticed this problem? Not sure if it's just an exporting bug or something else.

Dot density map zoomed in to show "sliced" dots

  • Can you include a bit more information about your data, the other layers (have you turned them off?), your export settings and process. Please edit your question to include this extra info.
    – Midavalo
    Commented Feb 15, 2017 at 18:30
  • Try taking a look at this technical article, but it may not apply to your situation.
    – mkennedy
    Commented Feb 15, 2017 at 21:55
  • Is it slicing the entire image (including background) or just the points?
    – Midavalo
    Commented Feb 15, 2017 at 23:21
  • It's just slicing the points, nothing else.
    – Will
    Commented Feb 16, 2017 at 19:04

2 Answers 2


I figured out the problem with the dot slicing - it occurs whenever I have a transparency applied to the dot density layer. No matter how slight the transparency (I tried it at 1% just to verify), it will export to an image file with the slices. But with no transparency, the dots render just fine.

  • There are several known bugs with ArcMap and transparent layers, making this believable. It's one of the main reasons I've moved parts of my workflow to ArcGIS Pro, where transparency doesn't throw so many wrenches.
    – Map Man
    Commented Feb 28, 2017 at 2:50
  • Transparency is one trigger for this problem. So are pictue markers and pattern fills. It is a known issue, as documented at this esri support page: support.esri.com/en/technical-article/000002772
    – cmrRose
    Commented May 10, 2018 at 14:06

Try playing with the options in the Advanced ArcMap Settings Utility. You can usually find this in C:\Program Files (x86)\ArcGIS\Desktop10.3\Utilities although this location may vary depending on where you've installed ArcMap.

In the Advanced ArcMap Settings Utility click on the "Print/Export" tab, and try adjusting (increasing) the values in Temporary metafile size limit and Output raster buffer size and see if either of those improve your results at all.

enter image description here

Note: I usually have these set quite high - 200MB for the Temporary metafile size limit, and 512MB for the Output raster buffer size - but I have 16GB of RAM and haven't run into low-memory issues (as warned about in the utility). If you do run into these issues, lower the values.

  • Thanks for the tip - I was able to follow these steps, but I'm still having the same issue.
    – Will
    Commented Feb 15, 2017 at 23:20

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