Copy/Pasting selected pixels bringing through pixels outside the selection?

[Throne777]

See screenshot. Why is it pulling through all these messy pixels that are clearly outside the selection when I copy/paste from one layer onto a new layer?

[walt.farrell]

In approximate terms, the marching ants enclose all the pixels that are 50% selected or higher. But outside the marching ants, you can have pixels that are from 49% down to 1% selected. Copy copies everything that is selected, whether it's 1% selected or 100% selected.

This can affect you if you have a selection made with feathering, or one made with the selection brush since that's based on edge detection and won't be selecting a clean line (as I understand it).

[carl123]

10 hours ago, Throne777 said:

See screenshot. Why is it pulling through all these messy pixels that are clearly outside the selection when I copy/paste from one layer onto a new layer?

Can you upload that Affinity document to the forum