An engineering drawing hatches every material differently; a map fills every zone with a tint. Both come down to a handful of shapes repeated thousands of times in a dozen colours — and the ordinary way of doing it puts a separate copy of the shape into the file for each colour it appears in.
One such pattern is laid down here in five colours and in five strengths of a single press ink, with the ordinary kind beside it so the cost is there to see: one against five. On a hatched engineering drawing or a map filled with flat tints, that difference is the size of the file.
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.
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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.
Eight choices of plate among the four usual inks, each with the small program that shows it printed underneath, and two inks the press carries itself used together, every strength of one against every strength of the other.
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 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.