I managed to solve the problem!

I thought that some extension could cause such a behaviour so I disabled all the extensions I use. I noticed that print preview started to work ok then.

So trying to figure out which extension causes wrong behaviour I enabled them one by one and finally enabled them all. Print preview still works as expected!

Thank you idrin for your help.

Let's try this URL
https://forums.opera.com/topic/12975/opera-beta-prints-texts-as-graphic/4

I press ctrl-p, the screenshot of preview window:
http://imgur.com/yW0MT05

Text looks blurry and cannot be selected.

In "more options" I have set 600 dpi (highest possible resolution) and when I print whole page it is still printing as graphics, in blurry quality.

You can easily check that by trying to select any text in the print preview window - you can not do it.

Now return to the webpage, select some text and invoke Print option (ctrl-p) and choose "selection only" to print only selected part of the webpage. Now the text is sharp, you can select in on the preview and printout is smooth.

My Opera 34.0.2036.24 (but as far as I remember also v.33 behaved like this) on Windows 10 keeps printing text as graphics. The text then becomes very blurry and is almost unreadable on the printout.

It does not depend on the printer drivers - the same behaviour is on any printer, even "Save as PDF". Newest stable Google Chrome on the same computer prints ok.

Could you please advise what can be the problem?