Hi Anna,
This means that the text in your PDF is being generated as glyphs (one small graphic for each character) instead of text. You will also find that the PDF file is very large. You need to check the Font Embedding section in Configuration > Publishing > PDF.
For the first check, just make sure that "Export all text as glyphs" is NOT on, and that NO fonts are excluded from embedding (you must embed ALL fonts for Russian). If this does not work it means that there are characters in your text that are not included in the fonts you are using. Windows then simply replaces the text with glyphs.
Before trying to change out your fonts in your entire project, first set the font embedding mode to CID, and if that doesn't work to Type3. Type3 will always work, but the text will not be quite so clear at higher zoom settings. If CID works for you then you will get the best quality with that.
In addition to this you should also check your PDF reference printer driver. HM uses a printer driver to generate PDFs, and the choice of driver can have a big effect on quality. You can access the reference printer driver settings in
View > Program Options > PDF. By default, HM will use the screen device driver, but you can often get better results by using a real printer driver. By the same token, some printer drivers can also cause problems, particularly optimized drivers from printer manufacturers. It is generally better to use one of the standard drivers supplied with Windows.
If the driver of your own installed printer doesn't work well you can activate and select one of the known good standard drivers included with Windows. You don't have to actually have the physical printer. Just add the driver with Add Printer in the printer section of the Windows Control Panel and then select it as your reference driver in Help & Manual. The standard Windows Brother HL-2040 and HL-2060 drivers deliver good results, and standard LaserJets and DeskJets are usually also OK. You can also use the Microsoft XPS Document Writer driver, which is always installed in all current Windows versions. However, this driver has the restriction that it can't be set to the higher output resolutions supported by more recent printer drivers.
Windows 10 no longer provides direct access to the list of standard drivers. To access it you must do this:
Select Add Printer, then click on "The printer I want isn't listed"
Next: Select "Add a local printer or network printer with manual settings"
Next: Accept the suggested port (this is irrelevant)
Next: Click on "Windows Update" and wait a couple of minutes for the list to display.
The last step can really take a few minutes. Go and make a cup of coffee...
After this you will be able to select a driver from the list.
Important Notes:
DON'T use "PDF printer drivers" like Adobe Distiller for this! This will not work properly and is actually counter-productive.
The output resolution and default paper size are set in the settings for the printer driver in the Windows Control Panel. The default page size set for the printer driver must be at least as large as the page size you have set in your print manual template. If it is smaller you will get clipping in your PDF pages.