Tileset edges are adding up

Heey

I have a 16x16 tileset. Their edges are adding up and I wanted them to share the same edge

So it becomes thinner

I'm not sure if I was able to explain it well, but here are some images of my issue:

I would like it to be like this:

Thanks!

If you want a single pixel border around your tiles, your tiles should have only one border drawn on either the top or bottom, and only one of either the left or right side.

Oosyrag is correct. Alternatively, you can set a one-pixel gap and have a colored background.