How do I create a fixed distance buffer in QGIS so only one side of the buffer (inside) is processed? I have a big shapefile to buffer and can't be expected to edit the nodes that lie outside each polygon. If I type a negative value in the buffer window, the entire inside of the polygon fills, even with a distance of 1.
The goal is to create a border to a polygon which is styled to the inside of that polygon. If there is another way about doing this do let me know.
Projection is British National Grid (EPSG: 27700)