tut: Background Transparency

Background Transparency in ArcGIS

For various complicated reasons, ArcGIS often has problems exporting or printing transparent backgrounds (for graphics, layers, symbols, data frames, etc.). Likewise, items that are semi-transparent won't always work. Things will often look fine in ArcMap, but when you export or print you'll have a white box surrounding the item that appeared to have a transparent background in Arc...

DATA FRAMES

Data Frames can be set to use a transparent background. These look especially nice for global maps using oval or circular projections. It doesn't always work, however, depending upon the data layers, symbology, etc. Often the background of the map will appear transparent in ArcMap, but when printed or exported there will be a white box instead of a transparent box... this is (somehow) a issue between ArcMap and the Microsoft print engine... (and apparently not easy to solve, as it has been an issue for years). The problem arises whenever you use a Raster layer in your data frame or Transparency in your data frame (No background is OK, but a semi-transparent layer is not). In some cases fill patterns will cause the problem (especially if they use a marker symbol for the fill). In some cases, exporting the map as a high-resolution (300 dpi or more) .tif (or.png or .gif) file and then printing that will work. Here's an example of the problem:

Note that there are two locator maps, each of which has rounded corners and (an intended) transparent background around the locator map. The locator map in the upper right looks fine. But the one in the lower left had a transparent background (which looked fine in ArcMap), but when printed or exported displays a white box...

Solutions...

One solution is to use Adobe Illustrator for your transparencies. Illustrator has a much more sophisticated set of tools and settings for dealing with transparency.

Another option is to just use a rectangular box (no rounded corners or global shape) for your data frames:

This works fine, but sometimes we don't want rectangular boxes...

Another solution is to locate the data frame on a white background (so the white box isn't an issue):

Another option is to use a solid fill (of whatever color you like, optionally matching your page background):

But the best option, is just to not use any raster data or transparencies:

Here's a compound example of a single map with different inset maps (using different combinations of raster data, transparency, etc.):

jpg or pdf file (export problems)                         .tif, .png or .gif file (no problems)

In all cases, the inset maps without raster data or transparency work fine...