A PDF page may include production-related content that falls outside the boundaries of the finished page. The production-related content can be a bleed area, print marks, etc. To control such content, a PDF page may contain as many as five separate boundaries:
[Media box] (default)
The media box is used when you open a non-page programmed document for the first time.
PRISMAprepare Go uses the media box of each page to assign the media size for that page.
When the media size has been assigned, the media box is no longer actively used by PRISMAprepare Go.
The media box always exists and it is the largest PDF box.
[Bleed box]
The bleed box may contain a bleed area in addition to the page content.
Usually, the bleed area is 3 to 5 mm larger than the trim box.
[Trim box]
The trim box defines the intended dimensions of the finished page.
The trimmed page contains the page content.
For each page, the trim box is equal to the page size.
In theory, the page size can be different for each PDF page.
[Crop box]
The crop box defines the region to which the page contents is going to be clipped.
The crop box may contain print marks, trim marks, color strips, etc in addition to the bleed area and the page content.
The print marks, etc., are removed from the original PDF page.
[Art box]
It can define a region within a page that is of special interest. It is rarely used by applications.
PRISMAprepare Go does not use the art box.
The trim box is always equal to the page size. The media box is not necessarily equal to the media of the document. For example, for a booklet, PRISMAprepare Go imposes two pages on one side of the media. Each page has its own media box which is not equal to the media of the booklet.
PRISMAprepare Go creates any missing PDF boxes when you open a non-page programmed document in PRISMAprepare Go for the first time:
If no trim box is defined, but a bleed box is defined, then the trim box receives the size of the bleed box.
If also the bleed box is undefined, but a crop box is defined, then the trim box and bleed box receive the size of the crop box.
Finally, if also the crop box is undefined, then the trim box, bleed box, and crop box receive the size of the media box. The media box is always present in a PDF page.
The following size rules apply:
[Media box] > [Crop box] > [Bleed box] > [Trim box].
PRISMAprepare Go changes the trim box automatically when the page size changes.
PRISMAprepare Go automatically maintains the relations between the PDF boxes according to the size rules.
[Media box] > [Crop box] > [Bleed box] > [Trim box].
The operator can change the PDF boxes manually.
For example, when you assign a smaller media to a page, you can select to reduce the page size. Now, PRISMAprepare Go automatically modifies the trim box. PRISMAprepare Go does not modify the trim box when you assign a larger media without changing the page size. If required, the operator must manually modify the other PDF boxes.
By default, the content of the bleed box is printed when the document contains a bleed area, otherwise the content of the crop box is printed.
You can change which content must be printed in the tab of the [Settings] panel. In this dialog box, you can select which PDF box must be printed.