Author Topic: Strange PDF rendering  (Read 562 times)

tb_nz

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Strange PDF rendering
« on: May 28, 2017, 05:50:42 am »
I am a total Scribus newbie, so please be gentle. :)
'm wearing my community help desk hat. We have a community newsletter that is printed once a month. It also is uploaded to our website. AFAIK it is produced on a Mac using Scribus, which I know nothing about.

The issue is that depending on how you view the PDF it renders quite differently.
Three attachments:

The first one is how it appears using Acrobat 9 - fuzzy and totally indistinct.
The second one is in Chrome - OK, but with weird thickened verticals.
The third is in Firefox - looks OK.
I can also say it renders OK with Acrobat Reader DC and also prints satisfactorily.

Different issues of the newsletter show different variations. Using Acrobat 9, sometimes the whole issue looks like the example, sometimes just page 1 is OK and the rest is bad (for example) and sometimes the whole thing seems OK.

I'm guessing it is something to do with the editor's production process, but she is reluctant to communicate about it (Why - who knows?). Looking at the PDF file properties it is a very old version - equivalent to Acrobat 6 - could that be an issue?.

Does anyone have any ideas about what is going on?

utnik

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Re: Strange PDF rendering
« Reply #1 on: May 28, 2017, 11:25:48 am »
could you show us one of the newsletters?

utnik

tb_nz

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Re: Strange PDF rendering
« Reply #2 on: May 28, 2017, 12:01:00 pm »
I don't have access to the original Scribus doc if that is what you mean.

I've been doing some experiments and if I create a Scribus doc using all the defaults and save it as PDF I get the same poor rendering if I look at in Acrobat9. I've attached that.

The environment is Windows 10.

utnik

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Re: Strange PDF rendering
« Reply #3 on: May 28, 2017, 12:18:17 pm »
your document doesnt contain any fonts. (not even as a subset…)
are the fonts embedded in the newsletters? – my guess is, they aren't!

without the hinting informations of the font file, the characters are normal vector objects and will render poor on low resolutions. (as i use a high resolution screen, i need to zoom out to 25% or less to see the problem, but it's there…)

utnik

tb_nz

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Re: Strange PDF rendering
« Reply #4 on: May 28, 2017, 12:37:02 pm »
Well that would certainly explain the poor rendering. As I said in my first post I know nothing about Scribus, so how do I make the fonts available? I think it is highly likely the newsletter document creator won't have a clue either.

utnik

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Re: Strange PDF rendering
« Reply #5 on: May 28, 2017, 08:22:00 pm »
…how do I make the fonts available?

under 'preferences' → 'fonts' you can select the fonts to use with scribus and define if they should be fully embedded or as a subset. (this will affect your future documents. for existing documents the path is 'document setup' → 'fonts'…)
in the .pdf export window there's a 'fonts' tab. here you may check, and change the settings.

…unfortunately the previous is not the whole truth!
some windows fonts have set a 'non embedding bit' – although the font license allows embedding in print files.
scribus respects this restriction, wile the microsoft office doesn't – i don't know if this is so by accident or by intention…
…to embed this fonts you need to hack them with a tool like fontforge (which is in a legal gray zone – but as the behavior of microsoft is in the same gray zone, i  wouldn't worry about it…)

utnik

tb_nz

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Re: Strange PDF rendering
« Reply #6 on: May 29, 2017, 12:19:06 am »
Thanks for the response. I've attached a screenshot of part of the "fonts" tab, which appears to show all the fonts are available - is that right? You'll have to take my word for it that all the fonts seem to be enabled. I've also attached the font properties from the PDF which seems to show that substitution has occurred. How if at all can I control that substitution? I've also done some experiments and it seems one always has to look at the fonts tab in the PDF export and select to embed the fonts. Is that right? I also noticed that sometimes it won't embed but adds the font to the outline set. Is that when the "do not embed" bit is set? It seems that it is when the fonts are outlined that I get the rendering problem.

 

palmate