The Portable Document Format (PDF) is a file format used to present and exchange documents reliably, independent of software, hardware, or operating system. In PDF, there are 5 different boxes that define the boundaries of the content within a page. These boxes are:
MediaBox
This is the boundary of the physical media on which the PDF content is to be printed. It defines the size of the page and is the largest box in the PDF. It is mainly used to provide room for extra data such as cropmarks, filename, date and time to help printing production.
CropBox
This box is optional. It defines the part of the page that is displayed on the screen, and the software uses it to determine the print area. Logically, it is smaller than the MediaBox and larger than or equal to the BleedBox or TrimBox. By default, if it is not specified, the software uses the dimensions of the MediaBox to determine the CropBox.
BleedBox
This is the region outside the TrimBox used for bleed. It is used for content that extends to the edge of the page and is trimmed after printing. The BleedBox is always larger than the TrimBox.
TrimBox
It is the most important box as this is the intended finished size of the physical page after it has been trimmed. It represents the final size of the page after the bleed has been removed. Aside from the ArtBox, the TrimBox is usually the smallest box.
ArtBox
This is the region of the page that contains the meaningful content, such as text and graphics. Usually the ArtBox defines the safe zone in relation to the edges of the TrimBox.
In Caldera software
- By default, CalderaRIP uses the CropBox. You can change this box in FileMan > Setup > RIP parameters tab > Use PDF Box.
- By default, PrimeCenter also uses the CropBox. You can change this box by applying a preflight profile.