3 Replies Latest reply on Apr 16, 2018 7:27 AM by sdedalus1

    Font rendering bugs in Acrobat?


      I'm getting some strange display artifacts in PDFs opened with Acrobat DC and Reader DC, both version 18.011.20038 on macOS 10.12.6 (Sierra).

      1) The ends of italic "s" and the bottom of italic "t" set in Charter (.OTF version 11.0d1e1, included with some versions of macOS) are smeared and too thin. There may be problems with other glyphs, I haven't checked extensively. Attached is a screen grab of the same PDF seen in Acrobat DC (top) and Apple Preview (bottom), set in 12/15, seen at 150%.

      Alice Charter 12-15 Sierra Preview (bottom) Acrobat (top) 150% sm.PNG

      The same artifacts are visible at 100% and other sizes. The PDF was generated by Mac OS 10.12.6 Quartz PDFContext, PDF version 1.3 (Acrobat 4.x), from Apple Pages, but the same artifact appears when exported from Word 2011 via "save as Adobe PDF", Acrobat PDFMaker 15 for Word, PDF version 1.3 (Acrobat 4.x).


      2) Although hard to detect in the Charter example, not all characters are aligned along the same baseline (see the "r" in "conversations"). This occurs in other fonts too. Here is an even worse example, of Melior in a PDF generated from QuarkExpress 8.15 engine, PDF version 1.4 (Acrobat 5.x). The top image is a screen grab from Acrobat, the bottom from Preview. You can see the wonky, jumping baseline especially in the "and" at the end of the first line and "trans-parency" in the last two. Again, it occurs at different sizes: I tested from 75% to 200%.

      Melior 9.75-12 Acrobat (top) Preview (bottom) 125%.png


      3) I also noted how much darker the same face (no matter which font) is in Preview than it is in Acrobat. It's almost like a semibold or regular vs. light! This makes it difficult to settle on the appropriate face for texts read as PDFs because they display so differently in different apps. These faces have the same darker rendering as found Preview, which I actually prefer, in other apps on macOS such as Safari, Chrome, Firefox, Word, Pages, etc. The rather light rendering in Acrobat in macOS appears to be similar to Acrobat in Windows, with Edge and Firefox on Windows rendering slightly darker than Acrobat but lighter than macOS. I assume this is just different font rendering technologies, but if there is any way for PDF producers to create a more standard display, I would like to know! (I'm on a 2014 retina 13" Macbook Pro, and checking/unchecking "font smoothing" in the General system preferences pane doesn't do much.)


      TIA for any insights.

        • 1. Re: Font rendering bugs in Acrobat?
          sdedalus1 Level 1

          Re: #1, I've tested BT Charter Pro, and ITC Charter Com (Std), and a free version of Charter in ttf, and they don't show the smeared glyphs. So Acrobat seems to be a problem displaying the Apple version of the font in particular (which seems to be BT Charter Std packaged as .ttc). This is unfortunate, because the Apple version is the only one I can get to show up in Microsoft Word (Office 2011).


          But here's #4: New Century Schoolbook LT Pro, set in 12 pt, screen grab at 125%. Acrobat on the left, Preview on the right. It's a little hard to see at smaller magnification, but it has extremely uneven color, including superdark capitals, almost like it's a bunch of different faces mixed together.

          Alice New Century Schoolbook LT Pro 12 Acrobat (left) Preview (right) 125%.png

          • 2. Re: Font rendering bugs in Acrobat?
            sdedalus1 Level 1

            Re #2 & #3, here is a zoomed screen grab of Melior 9.75 @ 125% in Acrobat. Notice the dancing baseline. Less noticeable here, but visible at smaller magnifications, is the way the tops of the "r" and "n" also seem too high compared to x-height. Seems the way the bottoms of counters "overshoot"  the baseline and the ways the tops of counters extend above x-height is rendered too strongly.

            Melior 9.75 Acrobat 125% large.png

            If you compare Preview's rendering of the same font and magnification, the round bottoms of the counters that overshoot the baseline are much lighter, producing a far more even and better looking baseline, seen here:

            Melior 9.75 Acrobat 125% Preview.png

            • 3. Re: Font rendering bugs in Acrobat?
              sdedalus1 Level 1

              Re #1, I have now also tested the version of Charter that ships with High Sierra 10.13.4 (v. 14.0d2e1), where it is again made available to users in all apps (it had been hidden from some apps in some earlier versions of macOS), and it still shows the same bugged display in Acrobat but not Preview.


              I have filed a bug with Adobe, please vote for it here:

              Font rendering bug with Charter.ttc from Apple – Share your feedback on Acrobat DC