Labels / 4 x 4 inch label
4x4 inch label PDF size
The 4 by 4 inch square label is the fulfilment and compliance label: shorter than a shipping label, same print head width.
The dimensions
One measurement in four units. Millimetres and inches are what a printer works in; points are what the PDF itself stores; pixels are only useful for checking a screen mock-up against the real thing.
- Millimetres: 101.6 x 101.6 mm
- Inches: 4 x 4 in
- Points: 288 x 288 pt
- CSS pixels: 384 x 384 px at 96 dpi
Where the size comes from
It runs on the same 4 inch thermal printer as the shipping label, which is the whole reason it exists as a standard. A warehouse that already owns the hardware gets a second label size for free by changing the media roll, and the square shape suits a code with a short caption better than a tall rectangle does.
What gets printed at this size
- carton content and compliance labels inside a shipment
- product labels where a 2D code carries the payload
- bin, shelf and location labels in a warehouse
Margins that survive a real printer
2mm to 3mm. The square shape means there is no long axis to absorb a mistake, so centre the code rather than aligning it to an edge. A Data Matrix or QR code needs a quiet zone of at least four modules on every side, which at typical sizes is about 2mm, and that has to sit inside your margin rather than overlapping it.
The CSS
4 x 4 inch label is not one of the six named formats the API accepts, so the size has to come from the document. Declare it in the page box and set prefer_css_page_size in the request.
@page {
size: 101.6mm 101.6mm;
margin: 3mm;
}
.code {
/* A 2D code must be square on the page. A percentage width with an
auto height will not stay square when the caption wraps. */
width: 45mm;
height: 45mm;
margin: 0 auto;
}The render request
With a custom size the options carry no format at all: the one flag tells the renderer to use the page box the document declares.
{
"html": "<!doctype html>...",
"options": {
// No named format. The page box in the document's own CSS is the
// size, and this flag is what tells the renderer to use it.
"prefer_css_page_size": true
}
}The mistake people make
Setting a square page and then laying out inside it with a percentage-based grid. Percentages resolve against different axes, so a nominally square code comes out a fraction wider than it is tall and the scanner rejects it. Use absolute units for anything that must be square.
Frequently asked
What is 4 x 4 inch label in pixels?
384 x 384 px at 96 dpi, at the 96 pixels to the inch that CSS assumes. That number is useful for comparing a screen mock-up against the page, and useless for laying out the document: use 101.6 x 101.6 mm instead, because a page laid out in pixels shifts whenever the render scale changes.
Can I pass 4 x 4 inch label as a format?
No. The API accepts six named formats: A4, A3, A5, Letter, Legal and Tabloid. 4 x 4 inch label is reached through the document's page box with prefer_css_page_size set, which is a supported path and not a workaround.
Does landscape need a different page size?
No. Landscape is the same rectangle turned, so it is set as an orientation rather than as swapped dimensions. Writing the width and height the other way round produces the same page and makes the intent harder to read later.
Other page sizes
Sizes that come up in the same conversation, and one from each of the other families.
4x6 shipping label PDF size
The 4 by 6 inch label is the standard thermal shipping label accepted by every major carrier, and the most common non-paper page size an API renders.
89x36mm address label PDF size
89 by 36 millimetres, or 3.5 by 1.4 inches, is the standard single address label on a desktop label printer.
A4 page size for PDF generation
A4 is the default page for business documents everywhere except North America, and the default this API uses when no format is given.
US Letter page size for PDF generation
Letter is 8.5 by 11 inches and it is the default page in the United States, Canada, Mexico, Chile and the Philippines.
80mm thermal receipt PDF size
The 80mm roll is the standard point-of-sale receipt: 80 millimetres of paper, a printable width of about 72mm, and a length that depends on the order.
Business card PDF size and bleed
85.6 by 53.98 millimetres is the ID-1 rectangle: the size of a bank card, and the business card standard across most of the world.
DL envelope PDF size and window position
DL is 220 by 110 millimetres, the standard business envelope in Europe, and it takes an A4 sheet folded in three.
Every page size, with dimensions
The full list, grouped by what the size is for.
Paste the CSS below into the playground and see the page box it produces.