PDF default units
PDF documents have a maximum dimension, defined in the specification: 14400x14400 units
In the default user space, one unit is 1/72 of an inch.
So, the default maximum file length is: 200 inches x 200 inches (14400/72) or, around 5 meters x 5 meters
To sum up, with 1 unit = 1/72 inches:
| units | inches | meters | |
|---|---|---|---|
| PDF max dimension | 14400x14400 | 200x200 | 5x5 |
PDF 1.6 user-space units
However, this limit can be bypassed if the application creating the PDF supports user-space units, defined in PDF 1.6 onward.
The maximum size is still defined as 14400 units, but the application can define the user unit.
The user-space unit can be defined as 1/30 of an inch (instead of 1/72), so the maximum size of the generated document will be larger.
Example
With 1 unit = 1/30 inches:
| units | inches | meters | |
|---|---|---|---|
| PDF max dimension | 14400x14400 | 480x480 | 12x12 |
Support of user-space units
From Caldera
Caldera software is compatible with user-space units:
- PrimeCenter generates automatically PDF files with the correct user-space units.
- CalderaRIP can process any custom user-space units PDF files.
Third-Parties
- With callas pdfToolbox, you can retrieve in the XML report the box sizes and "effective" sizes that indicate the real size taking into account the user-space units.
Apps not supporting user-space units:
- Adobe Creative Suite
Workaround for other editors
Full vector PDF
You can still work with a common trick design in a lower dimension (like 1/2, 1/4, or even 1/10) of the real dimension and use the RIP software scaling feature to rescale to the correct dimension.
This is a perfect workaround for a full vector PDF. It can be a problem when working with raster data inside the PDF.
Raster PDF
To be totally complete, you can play with raster file formats limits (at your own risk) as the printed result with low-resolution files can be disappointing and the perceived quality depends on the distance of viewing:
- JPEG is limited to 65 535 × 65 535 pixels, so:
- for a resolution of 300 dpi, you can reach around 218 inches (around 5,54 meters),
- for a resolution of 72 dpi, you can reach around 900 inches (around 23 meters).
- BigTIFF can support 64bits offsets so not really a human-limited dimension, but even if supported by CalderaRIP, it is generally not used as a design export format.
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