03-19-2017, 05:52 PM
I think I see the problem. Still a bit of a guess, but it looks like you have been stroking the selection to obtain those borders/bands.
Then it depends how you do that. It looks like you have been using the paint tool. This will introduce anti-aliasing (semi-transparent pixels) to 'smooth' a line, even a horizontal or vertical line.
To avoid this use the Stroke line option which will give cleaner horizontal / vertical lines. For thinner lines best turn the anti-aliasing option off under Stroke line as shown.
Then it depends how you do that. It looks like you have been using the paint tool. This will introduce anti-aliasing (semi-transparent pixels) to 'smooth' a line, even a horizontal or vertical line.
To avoid this use the Stroke line option which will give cleaner horizontal / vertical lines. For thinner lines best turn the anti-aliasing option off under Stroke line as shown.