Some presses carry six or eight inks rather than four. Some jobs have to lay black over a picture without touching the three colour plates underneath it. Neither can be said in the ordinary way of naming a colour, because naming a colour the ordinary way speaks to every plate at once, whether you meant it to or not.
Here a colour names exactly the plates it wants, so black can be laid over a photograph while the three colour plates under it stay clean, and a press ink can be used together with the ordinary four. A colour like that is not a number, it is a recipe — which is why the recipe is printed in small type under each panel it drew. Reading the two side by side is the quickest way to see what a plate actually receives.
Nothing is left out and nothing is simplified: this is the program exactly as it runs, for the developer who uses this library. The third is the description itself: a plain list of what the page has to say, which is what the service is sent.
Read the Rust source Read the Python source Read the JSON source
The document is lighter than it was, and every page still looks exactly the same. See this document's row in the table of every example.
Swatches in each of the three ways to say a colour — a grey as one number, a screen colour as three, a printing colour as four inks — each captioned with the instruction actually written into the file, and one mid-grey said three ways.
The same six colours said as bare numbers and then read through the screen profile the file carries, plus a ramp from light to dark and a sweep of measured hues: colour that still means the same thing on another screen and on a press.
Two inks the press carries on a plate of their own, each at ten strengths, a piece of work set in both, and the alignment crosses used to line the plates up — drawn in an ink every plate answers to.
A chart of house colours the file carries, and a drawing whose sixteen numbers are places in that chart rather than colours. The same drawing is shown twice through two charts: repainting a whole brand is one chart, not every drawing.
One pattern that states no colour of its own, laid down in five colours and in five strengths of one press ink: the fill says what colour to lay it down in. Beside them, the same hatch made of patterns that carry their own colours, which is one pattern per colour.
One drawing on three pages: a press sheet stating where the ink runs, where the blade falls and what is worth keeping, with trim marks; the same sheet cropped to the finished page; and a landscape page that states a quarter turn clockwise on an upright sheet.