If I print a pdf document from okular some pages it prints have low resolution that makes the text hard to read whereas some pages from the same document print fine with sharp, crisp text. Two of the pages have obvious printing errors when printed with okular: one has a compressed band where the text is 1/2 height, one has the top 1/3rd of one line of text missing. Again they print perfectly without okular. This appears to start when I changed from Kubuntu 14.04 to 16.04 so may be a recent problem. Since all the printer drivers etc changed at the same time I've tinkered with the printing subsystem and this appears to be fine - radically different printer drivers don't change the problem and print test pages are always good. I couldn't get acroread to work in 16.04 but I installed evince and this produces perfect print regardless of the presence of colour. The colour images in these pages printed using evince are also obviously sharper. Printing directly using lpr is also sharp. My guess is I've got 600dpi on good pages and <150DPI in bad - on my current document I'm printing >50% of the pages are blurry. I've tried the "greyscale" option in the print dialog but this produces the same result - low res colour pages. I tried "force rasterization" and the same result. Zooming the text on the screen always gives sharp results regardless of colour. Reproducible: Always Steps to Reproduce: Print colour pages from okular and you get low res prints Actual Results: Low res colour pages Expected Results: printing resolution should be independent of the presence of colour.
Unfortunately we can't have multiple bugs per bug report. A good example of why is because I'd like to mark the "no grayscale printing" bug as a duplicate of https://bugs.kde.org/show_bug.cgi?id=368758, but if I do that, we lose the other issue you reported. I'm going to do it anyway, and please feel free to open a new bug on the other issue if it isn't yet resolved. *** This bug has been marked as a duplicate of bug 368758 ***
I reported one bug and documented several tests - I didn't report "printing in greyscale" prints in colour, I reported " some pages it prints have low resolution"
Actually you reported multiple issues: one for the low resolution, another for the greyscale option not working (you wrote: "I've tried the "greyscale" option in the print dialog but this produces the same result - low res colour pages.") We still need to have one bug per bug report. If you want, we can ignore the greyscale issue in this but report, since it's already tracked by Bug 368758).
Sometimes is a bad description, you'll really have to be more specific on which files you're using and how you're printing them.
If you can provide the information requested in comment #4, please add it.
"sometimes" is as good as it gets! - if I had detected a pattern or cause and effect I would have mentioned it! The nearest thing I can recall it being like is an old version of okular that didn't always refresh the screen resolution properly when zooming in and out. I don't have this version of okular anymore and the bug is over a year old so I say "close" and I'll reopen it if I see this happening again...
Sounds good, thanks for checking back in! Please re-open if you see it again.