Articles
The Flint PDF library
Short, practical pieces on PDFs — fixing a typo, signing a contract, getting a file under 25 MB, picking the right format, dealing with awkward scans. 965 articles and counting.
PDF to JPG conversion low quality? Get sharp output
Low-quality JPGs come from low DPI settings. Choose higher resolution and sharp images result.
3 minReadPDF to PNG with transparent background: get the empty space
PNGs support transparency where JPGs don't. Convert to PNG to preserve transparent areas in PDFs.
3 minReadPDF to Word conversion losing formatting? Keep the layout
Format-losing conversions use weak engines. Better tools preserve structure cleanly.
3 minReadPDF to Word conversion missing tables? Get them back
Tables need a converter that detects them. Use a smart engine and structure carries through.
3 minReadPDF too large for Gmail? Get it under 25MB
Gmail's 25MB cap is firm. Compression typically brings PDFs comfortably under.
3 minReadPDF too large for iMessage? Send the document anyway
iMessage caps at 100MB but cellular reliability suffers above 20MB. Compress for smooth send.
3 minReadPDF too large for Outlook? Send it anyway
Outlook caps at 20MB for most consumers and varies for corporate. Compress to slide under.
3 minReadPDF too large for WhatsApp? Send the document anyway
WhatsApp caps documents at 2GB total but the practical limit is bandwidth. Compress for fast send.
3 minReadSigned PDF changes after editing: handle the broken signature
Edits break signatures. Once broken, re-sign or accept that authenticity is lost.
3 minReadSigned PDF shows invalid signature: diagnose and restore trust
Invalid signatures mean the file changed or the certificate isn't trusted. Each has a different fix.
4 minReadWhy does my converted PDF have no text layer? Add searchable text
Image-only output happens when conversion rasterises text. OCR restores searchability.
3 minReadWhy does a converted PDF have wrong fonts? Restore the typography
Wrong fonts post-conversion mean fonts weren't embedded. Re-export with proper embedding.
3 minReadWhy does Excel to PDF cut off columns? Fit it all on the page
Wide Excel sheets need page-fit settings or landscape orientation. Set before export.
3 minReadWhy is my PDF blank? Diagnose and recover the missing content
A blank PDF is almost never truly empty. Diagnose the cause and recover what's hiding behind the white pages.
4 minReadWhy is my PDF blurry? Restore sharp text and images
Blurry PDFs are almost always a resolution or compression problem. Spot which and get sharp text back.
3 minReadWhy is my PDF converting with extra pages? Stop the page bloat
Extra pages on conversion come from page-break mismatches. Adjust source or post-process the output.
3 minReadWhy is my PDF displaying the wrong orientation? Fix it permanently
Wrong-orientation PDFs have rotation metadata that doesn't match the content. Rewrite once and it displays correctly forever.
3 minReadWhy is my PDF form not saving? Keep filled fields filled
Forms that don't save use restricted templates or are filled in viewers that can't write. Flatten and resave properly.
4 minReadWhy is my PDF larger than the original? Stop the size inflation
PDFs grow during export when source apps embed extras. Re-export smart or compress after and the bloat disappears.
3 minReadWhy is my PDF loading slowly? Make every page open instantly
Slow PDFs are bloated PDFs. Compress them once and they open instantly forever.
3 minReadWhy is my PDF not attaching to email? Fix the upload now
PDFs that won't attach usually exceed size limits or trip security filters. Shrink or share differently.
3 minReadWhy is my PDF not displaying fonts correctly? Fix font substitution
Wrong fonts mean the PDF didn't embed them. Rebuild the file with proper embedding and your design returns.
3 minReadWhy is my PDF not loading? Diagnose the stall and fix it
PDFs that won't load are usually too big, partially downloaded, or hitting a viewer bug. Identify the cause and unstick it.
3 minReadWhy is my PDF not opening? Causes, fixes, and recovery steps
When a PDF refuses to open, the file itself is usually fine. Here's how to figure out what's blocking access and get it working.
4 minReadWhy is my PDF not printing in colour? Restore full-colour output
A PDF that prints monochrome usually has a print setting forcing greyscale. Fix it at print or rebuild the file.
3 minReadWhy is my PDF not searchable? Add a text layer in seconds
Unsearchable PDFs are image-only. Add a text layer with OCR and the find function works again.
3 minReadWhy is my PDF printing blank? Fix the print without the white pages
A PDF that prints blank has content the printer can't render. Re-flatten the file and it prints cleanly.
4 minReadWhy is my PDF rotated? Fix sideways pages permanently
Sideways PDFs aren't your viewer's fault — the rotation lives in the file. Rotate it permanently in one step.
3 minReadWhy is my PDF saying it's corrupt? Recover the content
Most 'corrupt PDF' errors come from truncated downloads or partial writes. Repair or rebuild and the content comes back.
4 minReadWhy is my PDF so large? The real reasons and how to shrink it
Most oversized PDFs have one of three culprits. Spot which one yours is and shrink the file in a single step.
3 minReadWhy is my PDF text fuzzy? Restore crisp, sharp text
Fuzzy PDF text comes from raster fonts, soft scans, or rendering bugs. Sharpen it by rebuilding the text layer.
3 minReadWhy is my PDF text not selectable? Make it selectable in seconds
Unselectable text means the PDF is image-only. OCR adds a real text layer and selection works.
3 minReadWhy is my PDF too small to print? Get readable output at full size
A PDF that prints tiny has a page-size mismatch. Fix the scale setting or rebuild the file to print at full size.
3 minReadWhy does my encrypted PDF show blank? Diagnose the lock
Blank encrypted PDFs may have render issues separate from encryption. Unlock and rebuild.
3 minReadWhy doesn't my PDF signature show? Make it visible
Invisible signatures mean wrong placement, transparent ink, or wrong layer. Place visibly and flatten.
3 minReadWhy does PDF conversion take so long? Speed it up
Slow conversions usually mean large files or OCR work. Compress first or use a faster tool.
3 minReadWhy does PDF to HTML conversion look broken? Improve the output
HTML is structural; PDFs are positioned. Conversion always involves translation; better tools translate better.
3 minReadWhy does PowerPoint to PDF lose animations? It always does
PDFs are static; PowerPoint animations are motion. Conversion can't carry motion. Use video for animated content.
3 minReadWhy does signature validation say modified? Understanding the warning
'Modified' means the file changed after signing. Sometimes intentional, sometimes alarming.
3 minReadWhy does Word to PDF change formatting? Lock the layout
Word-to-PDF layout shifts come from font and export settings. Embed and standardise.
3 minRead