When I print from CorelDraw fine black horizontal or vertical lines appear around some objects. So far, I have only observed it with objects which are either vector objects with a transparency or bitmaps with or without transparency, but not all such objects on a page are affected. The lines do not follow the original object border, but roughly a rectangle around the object. Lines are not solid, but irregularily interrupted.
When the same drawing is printed multiple times, the lines are exactly the same.
The lines do not show when the drawing is converted to PDF and then printed.Printer is a Canon MX870. I have updated printer drivers but that had no effect. Operating system is Win 10 64-bit. No other applications show similar problems.
See attached scan for an example. All the circles are circle shapes with either texture or solid fill, some with transparency. The background is a solid fill. The three horizontal rows of circles are all identical copies of the same (bottom) row.
Object hinting did not save the problem, but checking "Print as bitmap" did the job.
Thank you all for your help.