Why don’t my PDF links work after stamping?
It is a common problem that some PDF parsers do not recognize some types of links. The only library that faithfully recognizes internal links (such as Table of Contents) is SetaPDF-Stamper. If your external links (links leading outside the PDF to a website) are failing, try another library set, and if that doesn’t work, you can either try to repair your PDF, or upgrade to the SetaPDF-Stamper library.
If you cannot afford SetaPDF-Stamper, try the cynpdi-tcpdf 🌵 library set. Still no joy? You can get decent internal link (such as Table of Contents) fidelity using WooCommerce “Redirect Only” Download method and one of the free parsers included with PDF Ink. We don’t actually recommend this method for security reasons, but if you’re strapped for cash and desperate: we got you.
Repairing the PDF to keep external links isn’t fool-proof but sometimes works. First, try re-saving your PDF (“export as PDF”) with a semantic reader like Adobe Acrobat or Apple Preview. If that doesn’t work, try opening your PDF with Adobe Acrobat (paid version) or Affinity Publisher and look for invisible layers that might be on top of the link. Another text area might be large and overlapping the link, for example. Re-size the offending layer and then re-save the PDF. Sometimes to repair, the link can be deleted and re-created, then the PDF re-saved.
Most times it is 100% worth your time to just upgrade your stamping library.
Why doesn’t the first page get stamped?
If PDF Ink is skipping the first page, maybe the parser (TCPDI or FPDI) is not reading that page as part of the document. Is it possible the cover page was added as an afterthought to an existing PDF? FPDI and TCPDI struggle with some incrementally updated PDFs (existing PDF files which had content added later).
We recommend using a PDF viewer such as Apple Preview to delete the cover page, save, then drag and drop the cover page back into place from another open version of the same file, then ‘Export as PDF’ to save it. Alternatively you can try to repair (rewrite the PDF yourself, using something like Ghostscript or QPDF. This might help smooth out any problematic PDF syntax issues. Unfortunately we know of no other PDF reader (Windows or Mac) that can help the way Preview does for syntactically-incorrect PDFs. If you know of one, please reach out.
The silver bullet to solve this issue is to upgrade to using PDF Ink with SetaPDF-Stamper. The Seta libraries can handle cross-reference stream formats (PDF 1.5+), object streams, compressed xref tables, and other structural features that older parsers (TCPDI/FPDI) don’t support.
Why does the stamp go off the page, create new blank pages, or change the box size?
Your content text string or image is too big or long for the page size! The PDF writer created a blank page trying to accommodate the overflowing text.
Try decreasing font size, adjusting margins smaller, adjusting rotation, or using the X and Y fine tuners to move the content back onto the page. The built-in adjustments on the settings page ultimately allow for stamping on all document sizes. If your PDF has pages of more than one size, you might want to measure from the bottom of the page instead of the top (using a negative value for the Y fine tuner). You may need to edit your content if it is too verbose.
Why does the PDF have extra white space (or other changes that aren’t intended)?
If you find the base PDF is different after it is manipulated, it’s quite possible the PDF reading library struggled with the PDF’s syntax (see “trouble PDFs“). Either upgrade your PDF library, or attempt to repair the PDF.
Try re-saving the file with Apple Preview, or editing crop boxes/clip paths with Adobe Acrobat/Illustrator, then try again. Bottom line: your PDF must have reasonably predictable PDF syntax in order for a machine to be able to read it consistently across all applications. Upgrading to SetaPDF-Stamper can solve these issues because not only does it attempt to repair poor syntax, but at default it does not read the entire PDF into memory.
There are countless variations and interpretations of PDF syntax such that the application you use to view your PDF might show it differently than the next application.
A white border is added
This is basically the same as “extra white space”, above. A white bar or white border/margin is “added,” usually at the top of page. This is most often caused by a layer in the PDF the original designer was either unaware of, or believed wouldn’t cause issues. It’s causing issues now. You can either try re-saving the PDF as described in the paragraph above, or opening the PDF with an editor such as Adobe Acrobat and finding/deleting the extraneous layer.
It’s also recommended to try a different library set. Unfortunately it’s possible one parser is just “seeing something that isn’t there.”
I only get a bunch of blank pages
If you are encrypting your PDF and are getting all blank pages, your server might not support the encryption level you’ve chosen. This happens more often with AES encryption, so try RC4 instead. OpenSSL must be enabled on your host/server.
Inversely, if your subject PDF is already encrypted and you are not using the SetaPDF-Stamper library, the PDF structure will be read, but not the content. (It cannot be read, because it is encrypted!) Therefore, you will possibly see blank pages – but with your watermark on them. If you wish to watermark encrypted (protected/passworded) PDFs, you need to upgrade to using SetaPDF-Stamper. Or, if you are on a budget, do not serve encrypted PDF files to TCPDI/FPDI.
My settings are not saving / files are disappearing
In nearly every case this problem has had to do with server configurations, caching and firewalls. First, please make sure you have met the PDF Ink plugin requirements.
While setting up this plugin–or any plugin–it’s recommended you work on a non-production (offline or hidden “dummy” or “clone” site) site. This way when things break it is not detrimental to business. Development sites should have all caching turned OFF. There is nothing more frustrating than spending hours on an issue only to realize you were being serving a cached version of an old file that since had been replaced. If you cannot at least temporarily turn off caching, clear your caches frequently. Also, be aware you might be running more than one caching plugin, plus the caching on your server, plus browser caching.
If files (such as those in the wp-content/uploads/pdf-ink/ directory) are disappearing, turn off your WP security (like WordFence or Sucuri) plugin and see if files stop disappearing. If not, contact your host and make sure they have not set a security rule at the server level causing files to disappear.
Finally, make sure the LNT checkbox is unchecked in the PDF Ink Housekeeping settings.
My PDF watermark does not appear
If you have added a watermark to a page but it is not appearing, here are some things to try:
- If your original PDF is locked/encrypted, unlock it.
- Try a different PDF to make sure it’s not an issue with the PDF (similar to #1)
- Try another font, and make sure your font is large enough and opaque so it will be seen
- Try another PDF handling library. You can test higher-capacity (paid) libraries at https://pdfink.com/demo This will help rule out if your PDF is the issue. Some PDFs cannot handle being parsed with the open-source libraries that come included (free) with PDF Ink.
I am getting an error message
Check out our list of error messages to see if yours is listed, and maybe get an answer right away!