I got back a short run print job from a commercial digital printer recently. The background was designed as a block color, not a gradient or patter or anything, just all the one color; but when printed there were strange lines in it. The lines are very subtle but are definitely present, and quite obvious when you look at the result.
I took a scan in case it helps. The lines are not 100% horizontal they sort of wave a bit and it seems there are vertical lines also.
I'm asking here because the printers said it was a side effect of digital printing and there was nothing which could be done about it for short runs ( 200 ). He said on photos it would be masked by the photo but on solid block colours it would show. Can someone confirm my suspensions that this is not the case? I am surprised because I don't get any lines on my home printer.
I played with the contrast and curves a bit to bring out those lines a bit - there are several if you look carefully but the most obvious 2 are about 2/3 way down particularly on the left.