There are some smart people here who might be able to solve a mystery for me.
I have a Word document that I have edited (updated) a number of times, over several years, and created PDF files from by exporting using the engine built into MS Word 2013.
Suddenly in 2021 there was a problem. I subsequently noticed that the two most recently exported PDF files had horrible text kerning — worse than no kerning at all, I would say. So maybe I should describe it as ugly character spacing instead.
Malformatted screenshot: Reprinted screenshot: The spacing issue seems most noticeable with the positioning of the (thin) letters "i" and "l". Compare e.g. the word "simulation" in both screenshots, in the last line of the 2nd and 3rd paragraphs.
UPDATE: I've just noticed that even the size of the serif text is slightly different in the two screenshots. I don't have much sans serif text in the document, but it also seems to be a slightly different size, although perhaps not suffering from the ugly character spacing within words (but with different spacing between words). I forgot to mention that the blue ruled line under the heading also seems to have a different thickness in the two documents.
At first I wondered whether maybe the PDF file was OK, and it was just the display/rendering in Editor that had suddenly somehow messed up. But no, the same issue was found in other PDF viewers too. So it was definitely a problem within the PDF file. But I couldn't find an indication of the issue from looking over the respective document properties. Both files contained embedded fonts, and were created on the same computer using the same software, with access to the same installed fonts.
Could it be a problem with the Word documents? Maybe. But they displayed fine within MS Word.
Maybe an issue with inappropriate PDF exporting settings, or perhaps incompatibility with new formatting in the documents? After recognising the issue I tried re-exporting individual pages with different settings (still using the MS engine in Word), and could not reproduce the same malformed character spacing.
Eventually I just exported the entire documents again (in 2022; as per second screenshot, above), and this time the ugly spacing was gone.
I have a vague recollection of seeing some similar poorly spaced characters within text of PDF files found online on the odd occasion, and just assumed it was due to an 'incompatibility' or a 'bug' in the PDF creation tool.
Questions:
- Any ideas (in general) as to what causes this type of issue? And hence how to avoid it?
- Besides looking at the text carefully, is there a way to diagnose this — using PDF-XChange Editor or some other tool?
(For instance something in the metadata???) - Is there a convenient way to fix this in existing PDF files — using PDF-XChange Editor or some other tool — rather than starting from scratch and exporting a fresh PDF file from the source document (which might not be available)?
DIV
P.S. Sorry that this post is not 100% on-topic, but I've tried to wrangle the subject to keep relevant to the forum.
P.P.S. In extracting sample pages I set the options to 'copy' a single page within Editor, then manually edited to remove entire 'blocks' of text, and finally redacted a few words. Off-topic: I was interested to note that none of the source document's metadata were copied across into the new document.