print standard
A print standard is the published rule a file has to satisfy for a printing works to run it exactly as it arrives.
In more detail
Before a press starts, somebody has to know four things: which inks the colours are meant to be, where the lettering is, where the blade goes, and how far the colour runs past that line. A file that carries none of them costs a morning of telephone calls; a file that carries all four is opened and run.
A print standard is that list, written down once by the trade and published, so that a printing works can name what it wants in two words and a program can be held to it. For PDF documents the one everybody names is PDF/X.
What it does on a real document
The engine checks the four before it writes a single byte, and says which one is missing when one is. A refusal on your own machine costs a minute; the same fault found at the printing works costs a print run.
Ask your printing works which one they want, in those words, and the answer comes back in two: they name it every day.
Where it comes from, and why
The rules came from the printing trade rather than from the makers of the software. Firms exchanging jobs wanted one list they could all point at instead of a house style each, and the committee that wrote it was made of printers and publishers.
See it on a finished document
A sheet prepared for the printing works A sheet as it goes to the press The rules behind this word, and the texts they are read from
Glossary
- byte
- The unit a file's weight is counted in, the way a parcel is counted in grams. A thousand of them make a kilobyte, and a million make a megabyte — the size of one photograph taken with a telephone. A one-page PDF here weighs between fifty thousand and five hundred thousand, so a hundred of them fit in the space of two photographs.
- PDF/X
- A PDF a printing works can put straight on the press without asking anybody anything: the colours are stated in a way the press understands, the lettering is inside the file, and the page says where the blade cuts and how far the ink runs past it.
- CMYK
- The four inks a printing press lays down: cyan, magenta, yellow and black. A screen mixes light instead, so a document going to a press states its colours in inks, not in screen colours.
- blade
- The knife that cuts a printed sheet down to the finished page. It comes down on a whole stack at once, so it lands within a fraction of a millimetre of the line rather than on it — which is the reason a page printed to its edge is drawn larger than it will be.