Borders disappear from PDF when making accessible

[Tugce268177488u41]

Hi everyone

I've been given the task of making some 40 PDFs accesible, and autotagging makes some of the table borders disappear in some PDFs. 

They are pretty simple PDFs, with a headline and usually some tables. 

As per instructions, I've been doing the minimum accessibility requirements for them - 1) Run the accessibility check 2) Auto-tag 3) Run the accessibility check again 4) Fix primary language and title unless any other issues emerge.

The thin line option in PDF is already checked and I do not see anything in the Z-contents tab to change the order (in case some elements are disappearing under other elements depending on the order), because these table borders are not even recognised as a table. They are just there in the background, while the headers are marked as simple paragraphs. 

As a workaround I am now skipping the autotag option, opening the Reading Order tab, marking everything, then running the accessibility check and fixing other issues.

Just curious to see if anyone else is experiencing the same problem.

SUM: Autotag (accessibility) makes the borders in PDFs disappear.

[mindyd813]

I have been having similar issues! A flyer I created with lots of graphic elements has several images just disappeaar when I autotag the document. In the past I have also had elements disappear as I am editing the Reading Order. Is this a glitch??

[Abambo]

It would be nice to get examples!

[mindyd813]

Here is the before and after of my flyer. The only thing I did was click Autotag!

[S**P***]

so was there ever a solution/fix to this?  or just keep trying to do a workaround?

[S. S]

Hi @S**P***,

Hope you are doing well. Thanks for writing in!

I believe this is what's happening here: 

Auto-tagging restructures the PDF’s internal content order. Thin lines or backgrounds may be pushed behind other objects or even temporarily hidden because Acrobat reinterprets them as non-semantic graphics. Often, the lines are still physically present in the PDF, but are not visible due to stacking or because they were not tagged or recognized properly.

To fix this:

1. After tagging, open the Content panel in Acrobat Pro and look for the missing border elements. They may exist but be hidden behind other items. You can drag them up the stack to bring them forward visually.

2. Or, if you have tables or graphics with borders, do not use Auto-tag for those pages. Instead, manually tag using Reading Order tools: drag-select the table area & tag it as <Table>; assign <TH> and <TD>, then fill in alt-text or summaries as needed.

Let me know if this works for you.

Regards,
Souvik.