Methods for creating internal buffers for cartographic effect

January 13 2010 | 2 comments
Categories: Cartographic Design, Cartographic Effects, Cartographic Representations

In the past I have created internal buffers, or buffers inside of polygons, to mimic a cartographic effect I've seen often in published maps. The purpose is to help delineate boundaries more prominently between states, neighborhoods, etc. by making the internal buffer a slightly darker shade than the polygon it resides in. I've attached an example.

I'm interested in other methods to achieve this effect. Can this be done using cartographic representations?

We typically refer to the buffer effect inside or outside of a polygon as a tint band.  A small piece of cartographic trivia: National Geographic who is well known for using this effect calls them "buffalo tints".

We have written a few blog posts on how to achieve a similar effect in ArcMap:

Quick tint bands

A quick clean method for insetting polygon outlines

How to produce tint bands for boundaries

The second link above outlines a method using cartographic representations. This uses the Donut geometric effect.  What this effect does is it "cuts a hole" in the polygon (hence the name donut). If you also want a fill color with this method, similar to the graphic you attached, you will need to add a new fill layer, apply a color to it and then move it under the donut fill layer in the representations symbology dialog.  Then, you can apply transperancy to the entire feature class (Properties > Display).

To read more about the Donut geometric effect as well as other effects available in cartographic representations read this list of geometric effects

Follow up posted by Philip Uhl on Mar 15 2010 10:52AM
I tried the quick tint bands method. I think I like the effect. When you have lots of polygons of different areal size it can be a pain, but you have the bonus that the symbology changes when boundaries change. That was the main problem with creating another layer of internal polygon buffers.
Good! posted by Aileen Buckley on Mar 15 2010 12:34PM
Glad to hear you found a solution. The thiurd blog entry listed above might also provide a nice solution for you.