The areas a page states
State what reading software shows of a page and what a printing works does with it: the cut, the ink overrun, the useful area.
Summary
When a printer makes a business card, the ink goes onto a larger sheet and the card is cut out afterwards. So that the colour truly reaches the edge, it runs a little past the cut: the blade never falls in exactly the same place twice. Each of these boxes is a rectangle, given by its four edges — left, bottom, right and top — and it travels with the page.
Technically
Written at the top level of a request, under
"page_boxes"
page_boxes writes, page by page, the four boxes a PDF knows beyond the sheet itself, in points: /CropBox, what reading software shows and prints; /BleedBox, the ink overrun; /TrimBox, the cut; and /ArtBox, the useful area. Each box stays out of the file until the request writes it, and reading software then falls back to the /MediaBox. A box running off the sheet is accepted: reading software intersects it with the sheet, so it simply says more than it is worth.
Request schema
-
page_boxes— array, optional, empty by default. -
page_boxes[].page— integer ≥ 1, required. The page the entry is for. -
page_boxes[].crop— object, optional. What reading software shows and prints. Anything outside stays in the file and stays there for whoever wants it back. -
page_boxes[].bleed— object, optional. What the press lays ink on, ink that runs past the cut. -
page_boxes[].trim— object, optional. Where the blade falls: the page as it leaves the bindery. -
page_boxes[].art— object, optional. What is worth keeping of the page, what is drawn on it without its margins. -
Every box has
llx,lly,urx,ury: numbers, all required. They are the left, bottom, right and top edges, in points up and across from the foot of the sheet.
An entry says what is done with a page, not that there is one: a page named past the end of the document leaves the document as long as it already was. A page named twice takes the last entry, whole.
A whole request that creates a PDF
{
"page_boxes": [
{
"page": 1,
"bleed": { "llx": 9, "lly": 9, "urx": 586, "ury": 833 },
"trim": { "llx": 18, "lly": 18, "urx": 577, "ury": 824 }
}
],
"standard_fonts": [{ "name": "sans", "face": "helvetica" }],
"items": [
{
"type": "rect",
"rect": { "llx": 0, "lly": 0, "urx": 595, "ury": 842 },
"fill": [0.93, 0.95, 0.98]
},
{
"type": "text",
"rect": { "llx": 60, "lly": 740, "urx": 535, "ury": 765 },
"content": ["The colour runs past the cutting line"],
"font": "sans",
"font_size": 14
}
]
}The sheet, and what is laid under it
The size of the pages A size of its own for certain pages The unit a page is measured in The shapes a page lays over what it draws Which way up a page is shown How a page arrives, and how long it stands How far a supplied PDF is allowed to unpack The template under the pages
Where to go next
Every JSON key of a request, in one page The other forty-one settings of a request