I'm importing a .eps file, and if I zoom 400% or more, I can see a thin grey line along the top and right edges. The file seems to be using pt units. I'm not finding a way in Affinity Designer to get rid of that.
I found the background layer is a curve, but there is no object for the grey line and there seem to be no edge/bevel effects.
I tried changing the file units, with no result.
I tried making the canvas smaller (trying to crop the edge out), with no result other than making it bigger.
I tried tinkering with image options when exporting to a PNG, with no luck.
I had to later crop the exported PNG image in order to remove those two lines.
This seems like a situation which should often arise, but I haven't yet found what Files setting nor Export option which can deal with it.