Which plate of a separated sheet a page is
Say that a page is one plate of a sheet, and name the ink it is printed in.
Summary
A colour job is printed one ink at a time: a plate for the black, a plate for the red, a plate for the varnish. A document can carry those plates as pages and say so — this page is the red of sheet one, that page the black of the same sheet — and a reader then shows the sheet whole rather than as four pages that look wrong on their own.
Technically
Written at the top level of a request, under
"page_separations"
page_separations writes the /SeparationInfo of a page: the ink the page carries, and the sheet the page is a plate of. Pages sharing a sheet number are the plates of one sheet, and a sheet of a single plate is a page printed in one ink. No colour book is read: the colorant is the caller's own name for the ink. space names a colour space the request declared, so that a reader knows what the plate's tints come to; a name the request never declared is refused.
Request schema
-
page_separations— array, optional, empty by default. -
page_separations[].page— integer ≥ 1, required. The page this plate is. -
page_separations[].colorant— string, required. The name of the ink, as the press knows it. -
page_separations[].sheet— integer, required. The sheet the page is a plate of; pages sharing it are plates of the same sheet. -
page_separations[].space— string, optional. The declared colour space the ink is stated in.
A page named twice takes the last entry given for it, whole, and a page nothing names is a page of its own rather than a plate.
A whole request that draws it
{
"page_separations": [
{ "page": 1, "colorant": "Black", "sheet": 1 }
],
"standard_fonts": [{ "name": "sans", "face": "helvetica" }],
"items": [
{
"type": "text",
"rect": { "llx": 60, "lly": 740, "urx": 535, "ury": 765 },
"content": ["The black plate of the first sheet"],
"font": "sans",
"font_size": 14
}
]
}Colour and how it is shown
The device the colours are stated for Declaring colour beyond red, green and blue What a page's bare numbers mean A colour sliding into another Opacity and how colours mix A cell repeated to fill a shape The space a page mixes its colours in
Where to go next
Every key of a request, in one page The other forty-one settings of a request