Two PDFs land in your inbox. One opens instantly, sized right, named clearly. The other is 60 MB, called `Doc2.pdf`, and the signature is on the wrong page. You'll trust the first sender more than the second, instantly.
Here is what makes a PDF actually shareable.
Under 10 MB
The single biggest determinant of shareability. Files over 10 MB bounce from corporate inboxes, clog Drive quotas, and look unprofessional. Compress before sending — typical reductions of 60–80% with no visible quality change.
For truly large deliverables, share via link, not attachment. Email is for files under 10 MB; link sharing is for everything else.
Named like a deliverable
`Acme_Proposal_2025-08-15.pdf` reads professional. `final-FINAL-v3.pdf` reads amateur. Five seconds of renaming is the cheapest credibility you can buy.
Dates, context, doc type. That's the formula.
Signatures flattened
If the PDF is signed, the signature is embedded in the page pixels, not on an editable layer. Flint flattens automatically. Unflattened signatures are a security flag — they signal that the document can be tampered with.
Test: open the received PDF and try to drag the signature. If it moves, it's not flattened.
Structured with clear page breaks
Cover page, table of contents (for long docs), one section per topic, clean page breaks. A PDF that mid-section breaks across a page looks rushed; a PDF with clean section breaks looks intentional.
This happens in the source document, not in the PDF. Format the source properly before exporting.
Metadata cleaned
Open Document Properties on any PDF you receive. The author name, original filename, software used — that's metadata. Often it leaks the source document's previous client name, embarrassingly.
Clean metadata before sending. Set author to your name, title to the document title, no traces of the previous use.
Searchable text, not scanned images
If the PDF contains text, it should be searchable text — selectable, copyable, indexable. Scanned PDFs are images of text, useless for search.
For scans, run OCR before sharing so the text is searchable. The recipient will thank you.
Password-protected if sensitive
Anything carrying financials, PII, or commercially sensitive numbers should be password-protected. Send the password through a separate channel.
Don't password-protect marketing material — friction without benefit.
Cover that earns the next click
The first page sets the tone. A clean cover with the document title, the date, your branding, and the recipient name does more for trust than any other single page in the PDF.
Thirty seconds in the source document to design a decent cover; permanent uplift in how your PDFs land.
FAQ
Do these checks apply to internal PDFs too?
Lighter version, yes. Internal PDFs can skip password protection and worry less about branding, but size, naming, and flattened signatures still matter.
How long does the full checklist take?
Two minutes per PDF, less once it's routine. It's the difference between an amateur send and a professional one.
What about accessibility?
Important for public-facing PDFs. Tagged PDFs (with structure for screen readers) take more effort to produce but matter for inclusivity and many compliance requirements.
Should every PDF have a cover page?
Documents over 3 pages, yes. Short PDFs (a one-page invoice, a single statement) don't need one.
Eight checks, two minutes, polished outbound PDFs every time. Run your next send through Flint and feel the difference.