Text and Curves with Stroke Outlines Exports Badly to PDF

[Nat20]

Hello, all! I come seeking help with a persistent issue that's causing me a great deal of trouble. In Affinity Publisher, when I create text with a thick stroke around it, it looks fine in Publisher but is sometimes flawed when I export the file to PDF. (It seems to have something to do with the size of the font as compared to the thickness of the stroke, so it doesn't always happen.)

I've tried converting the text to curves before exporting, but the problem remains. If I rasterize the text (or curves) the problem goes away, but rasterizing inevitably causes a loss of sharpness, and I'm worried the rasterized text will look blurry when it's printed.

The problem doesn't occur when I export to an image format, only PDF.

I'm using Affinity Publisher 2.1.1 on Mac OS Big Sur 11.7.7 and viewing the PDFs in Preview.

Any ideas? This is causing me no end of trouble with files that need to go to the printer ASAP. The ideal solution would be to stop this export bug from arising, but I would also take a way to ensure that rasterizing text/curves keeps them as sharp as the originals. Thanks so much!

Here are some pictures showing the problem. Ignore the relative sizes of the text, these are quick screenshots so the zoom is inconsistent.

Artistic text as it appears in Publisher:

 

Exported to PDF with embedded fonts:

 

Exported to PDF with text converted to curves is pretty much identical:

 

Exported to PDF with the top line rasterized. The rasterized line is noticeably blurrier than the second line, which isn't rasterized. (Note that the bottom line doesn't exhibit the bug, I think because the font size is larger but the stroke width is the same.)

 

[firstdefence]

Can you create an example affinity file and upload it please?

[Nat20]

Certainly! Here's something. Of course not everyone will have the fonts I'm using, which led me to try it with a few different common ones, most of which didn't exhibit the problem, at least at the size and stroke width I'm using. The font I used above is Blacklist, which can be found for free online. The font in my sample file is Bodoni 72, which is either pre-installed on Macs or available free online, and also exhibits the bug (and some other weirdness) at this size.

I've also attached PDFs using Blacklist and Bodoni, so others can see if the bug displays on their machines as well. These were exported with fonts embedded, rather than converted to curves.

Thank you so much!

stroke_export_test.afpub stroke_export_test_blacklist.pdf stroke_export_test_bodoni.pdf

[firstdefence]

In the apub file there is a corruption on the letter 'Y' If you zoom in on the top left portion it will not render correctly when zooming in. Actually zooming in on a lot of the text will display stroke corruption.

[kenmcd]

APub (and Designer) can have problems with TrueType outlines with strokes applied.
It is as if it simply cannot figure-out the mixed curve types.

Bodoni 72 included with macOS is an old TrueType font (not OpenType-TT).
So you are dealing with applying a stroke (PS curves) to TrueType outlines.

I tested your APub document with an OpenType-PS version of the font (.otf).
And it looks fine:

So use an OpenType-PS (.otf) version of the fonts.

[firstdefence]

Always an education @kenmcd thanks.

[R C-R]

5 hours ago, kenmcd said:

Bodoni 72 included with macOS is an old TrueType font (not OpenType-TT).
So you are dealing with applying a stroke (PS curves) to TrueType outlines.

FWIW, the Book style of that font seems to work OK with strokes applied but the Bold style clearly does not.

[kenmcd]

Using OTF does not seem to work with the Blacklist fonts.
Both the Blacklist-Bold.otf and Blacklist-Regular.otf still have the artifacts.

Found the Blacklist font family here: https://www.dafontfree.co/blacklist-font-free/
Includes both TTF and OTF fonts.

So while changing to OTF worked for Bodoni 72, apparently that is not the case for the Blacklist fonts.

This issue with stroke-applied has been posted before, and changing to OTF has worked in some other cases.
So not sure what is going on here.

Saw nothing odd with the Blacklist OTF font(s) glyph outlines.
(the font family does have broken name fields, but that should not affect this).

Appears APub simply cannot get the apply stoke correct.

 

[R C-R]

6 minutes ago, kenmcd said:

Appears APub simply cannot get the apply stoke correct.

Just APub or all of the Affinity apps?

[Nat20]

Hello, all! Thank you so much for the assistance, and apologies for the late reply (I was traveling this weekend).

I've checked, and I'm already using the OTF version of Blacklist, so unfortunately that's not the cause of my troubles. It is very good to know about TrueType fonts, though! I don't see the corruption mentioned by @firstdefence when I zoom in, but that may just be me.

To @R C-R's question, I tried exporting the same text to PDF from Affinity Designer 2 and it exhibited the same bug. However, that did suggest something of a workaround: from Designer, export just the text to a hi-res png, then import that image back into Publisher and set it in the file where the live text is now. It's clunky, and I'm still a bit worried that the text-as-image won't print as sharp as actual text would, but it's worth a try.

Unless anyone has any other suggestions—but it sounds like this is simply a bug in Affinity. Is there an official process for me to open a bug report with them?

[DWright]

This issue has been logged with our developers

[Nat20]

3 hours ago, DWright said:

This issue has been logged with our developers

Thank you!

[Nat20]

And for anyone curious, exporting a hi-res PNG from Designer and bringing that into Publisher is a usable workaround for the time being. The rasterized curves that Publisher puts out don't print well (they're noticeably blurry), but Designer's exported PNG looks fine when printed alongside PDF text.

[kenmcd]

Another option is to use an actual outline font.

If you are using just some letters for a headline or something, this may work...

Did a quickie conversion to an outline font.
As expected there are the usual quirks on some characters. Fixed a few.
Normally you would spend quite a bit of time tweaking the quirks.
And adjust the advance width for the now wider characters, etc., etc., etc.
But if you just need a few letters that you can tweak, and manually kern...

BlacklistOutlineBold.zip

 

[kenmcd]

@DWright

I remembered a similar problem report with a different font (Gotham).
That case also involved stroke outlines and artifacts on export.
 https://forum.affinity.serif.com/index.php?/topic/168240-strange-font-output-error/

The root of the problem is the apply-stroke cannot handle when two nodes in the font are very close together.
In that other thread I applied simplify to the character outlines to turn two very close nodes into one node.
I did the something similar here with the Blacklist Bold font and merged nodes which were only 2-3 font units apart.

This image below is the top left corner of the capital I character in the original Blacklist Bold font.
Those two highlighted nodes are only two units apart.
There are similar close nodes in the other characters (where you see the artifacts in the output).

So what I did is merge those nodes in the characters used for the test.

The test images below are: Export to PDF, and then export to PNG from the PDF.

This is the BEFORE test (the original font).

This is the AFTER test (after modifying the font to merge the close nodes).

Note no artifacts.

If Affinity is ever going to support variable fonts this must be fixed.
Variable fonts have nodes that are very close to together, and even overlapping.
And obviously a lot of static fonts also have nodes which are close together.

If you want the Before and After modified fonts, both Gotham and Blacklist,
just give me an upload link (Gotham is commercial).