Creating a ring shape around a polygon

[Mancunian]

Hello!

I have several english counties I have to create a buffer around. I have been using the Buffer tool, but in the output I don't see a ring but rather the county as well as the buffer included. How do I get my shape to be a buffer around the boundary of the county and be hollow in the middle?

[CharlieS · Accepted solution]

@Mancunian

After you create the buffer field, the Spatial Process can cut the original spatial object from your buffered object. When you use the Buffer tool, check the box to include the original object. Then a Spatial Process tool can "cut" the first from the second object, leaving the buffer zone only. 

If you're looking for a symmetrical ring, that's a bit different (but still possible)

Solution example attached.

[Mancunian]

Thank you for this, it is the symmetrical ring I require around the boundary of the county. How do I go about doing this?

[CharlieS]

@Mancunian

The symmetrical ring version is also built into the solution above.

That option starts by assigning a centroid to the polygon. Then the polygon boundary is split into points (Poly-Split tool) to determine the point furthest from the centroid. The distance to that furthest point is used (plus a buffer) to create a symmetrical trade area around the original object. After that the Spatial Process tool is used like the other solution to cut the original object from the new buffer object.