After you've imported design files via our plugins, you can choose to ignore the borders between layers when inspecting the layer data in Development mode.
As you can see in the below image, there are three rectangles with the same size (300*300px), and border width (30px).
If you don't select “Measurements between layers ignore borders”, the measurements between these rectangles will include the width of borders, counting 30px in.
If you select “Measurements between layers ignore borders”, the measurements between these rectangles will ignore the width of borders, excluding 30px.
With that option selected you still find that the shown numbers are incorrect, it may be only because you have also selected the “Spec includes extension area” in your plugin. Once you've selected that option in your plugin, borders are already included in the specs. If you also select “ Measurements between layers ignore borders”, the borders will be excluded again.
To ensure you get the right measurements, you can untick “Spec includes extension area” in your plugin or unselect “ Measurements between layers ignores borders” in Development mode. Select only one of them.
