A minimal PDF
Two identical pages carrying the bones of an invoice in plain shapes, and not a word of text: a file of a dozen kilobytes, with no font embedded.
Pages, text and fonts
The page itself, the words on it, and the font — carried inside the file so the page looks the same everywhere.
A page has a size, like a sheet of paper, and words are placed on it. The font — the particular shape of the letters — is kept inside the document itself rather than fetched from whichever machine opens it.
That single decision is what makes a PDF worth sending. Give the file to a customer, a supplier or a printing works, and every one of them sees the page you laid out, in the font you chose, at the size you chose, whatever is installed at their end.
What it saves you
- The page looks the same on every machine
- Nothing is quietly swapped for something similar, so nothing shifts and nothing overflows.
- The file stays small
- Only the letters actually printed are kept. A one-page letter carries the few dozen characters it shows, not the several thousand the font contains — which is most of its weight.
- It still opens decades from now
- Nothing in the file depends on a program that has to still exist. That is what makes a document worth keeping, and what an archive service asks for before it will take one.
See it done
Showing page one before the file has arrived
The same document written twice, the ordinary way and with its first page moved to the head of the file, with how much of each must arrive before page one appears.
Making the file smaller
The same document written twice, plainly and packed, with what each one weighs and what the packing saved.
A document that reads freely and asks not to be copied
A page that opens with nothing typed and prints like any other, and that asks the reading software to leave its text where it is. Every word of it is scrambled inside the file.
A document that asks for a password before it opens
A page nothing shows until its password is typed in: no first line, no preview, no picture of it anywhere. The password is given on the example's page, to be tried.
Fonts embedded in the file
Text set in a font embedded in the file, cut down to the letters actually used, and still searchable, copyable and readable aloud.
Letters you draw yourself
A tick, a cross and a dash drawn by the program, added to the document as a font, and set among ordinary words.
A page that carries no font
Four fonts all reading software draws on its own, set on one page, so the file carries no font at all — and the example weighs the same lines both ways to say what that saves.
A page set in a font from 1990
A font in Adobe's oldest format, the kind a print shop bought twenty years ago and almost nothing reads any more, carried whole into the file. Every figure the page states about it was read out of the font itself.
A page whose letters cost one byte each
The same three lines written twice over — the ordinary way, then with each letter kept as a single byte — and the page states what each of the two came to. The short way also lets the space between the words of a line be set, which the ordinary way does not.
Dashed and dotted lines
Dashes and dots, the shape of a line's ends, the shape of its corners: each drawn as one line under those settings. The statement at the bottom is ruled with dots, and its total held off by a dashed line.