How page box information interacts with Sierra

Many people don’t realize that there are a lot of internal measurements for each PDF (and each page within the PDF).   These determine the page size and bleed in Sierra.  These measurements (page boxes) are invisible by default, but can be viewed in Sierra.   What do these internal measurements mean, and how do they impact Sierra?  The five boxes/internal measurements are:

Media Box – This is the physical dimension of your PDF.  If no other box information is found, Sierra will use this measurement for the trim box information.

Trim Box – This is the finished trim edge of your printed product.   If you have crop marks in your file, this is the box that will fall in line with the crop marks.  This is what Sierra uses to determine the size of your page(s).

Bleed Box – This is the area beyond the trim box that contains your bleed information/objects.  Often PDF files are incorrectly made with the bleed value set to 0” (the distance beyond the trim edge).  By using this value (0”), no bleed elements may show up when creating the PDF file in some programs.

Crop Box – This is the viewable dimension of your PDF.  Often set to the trim size, this value has no impact in Sierra, only when viewing the PDF in Acrobat.

Art Box – This is the physical dimension of the artwork elements (not including crop/registration marks) on the page.  This is the only box that may change from page to page, and still be okay as Sierra does not utilize this information.

So why does any of this matter?  Sometimes, you can have a PDF that cause size/position issues within Sierra, but everything looks fine in Acrobat.  The issue is usually with the page boxes not matching each other, or they are all the wrong size (e.g.: A4 instead of Letter).  If there is ever a mismatch, Sierra will try to pick a single size for the template, and make all the pages conform to that.

When Sierra is fed a PDF with different page boxes,  the results can be odd sized template pages, causing an error at the RIP, and/or repositions what you are supposed to see within the 8.5x11 page.

Okay, but how do I fix it?!?  You can change the page boxes within Sierra itself.  For the example below, let’s say that we found that page 2 (of our PDF) has different page box sizes than the rest of the document, and is rotated.  That will need to be fixed before we start creating a template.

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To open the page editor, simply double click on the offending page in the Reading Order.   That will bring up a new window.   Here you can clearly see that something is very wrong with this file.  It is rotated, and a large portion of the type is beyond the Trim Box (represented by the green line). In this window, you can edit the sizes of the Trim, Bleed, Crop and Art boxes, make rotations, and apply scaling.  You can make changes to the boxes by selecting the specific page box you want to adjust, and enter/change the numeric values, or by dragging/pulling the color lines themselves

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First, rotate the page. Using the Page Positioning tools.  For this example, I am rotating clockwise to match the other pages.

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Now we have the orientation the same as the other pages, but our page box information is still incorrect.

At this point, I would like to see what the page box information looks like on the other pages of the PDF.  At the bottom left of the screen, you will see a series of icons.  The icons to the far right edge will let you flip through the pages forward and back.

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If I go through some pages, I can see what the page box information is for the other pages (just for a comparison).

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So now I see that the other pages have all the boxes set to 8.5” x 11”.  Now I go back to page 2, and make some edits.  You cannot edit the Media Box.  You can edit the Trim, Bleed, Crop, and Art boxes two different ways.   The first is to click on the box name in the list.  You will see anchor points appear on the page box.  Now you can resize the box as you need.  Any changes will be reflected in the numeric display.

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The other way to adjust the page box information is to select the box you need to change, then enter the numeric values.  The colored boxes in the display will move accordingly.

Once the change(s) has been made, you can apply this change to multiple pages if you need by clicking on the Apply to Pages button under each section.  When you are done, click Save (lower right corner), and Sierra will now pull in the updated settings.