Crop Marks
The crop marks on all four corners of an exported document dictate where the printed piece should be cut.

Bleeds
Extending an element past the edge of the art board to the bleed line in your document ensures that it will run off the edge after its been printed and trimmed.

Bleed size:

The standard bleed is usually .125 in but can vary by project. Ask your printer what their preference is for bleed set up and file export. Some vendors prefer not to have crop and bleed marks because it makes the artwork have to be printed on a larger piece of paper which can be costly.

◀ Crop and bleed marks on an exported file.

Setting up bleeds
in Adobe InDesign

• In the Bleed and Slug section of the Document Setup dialog box you'll be able to specify your bleed sizes for the top, bottom, left and right sides of your artboard.

• The standard bleed size is 1/8 of an inch (.125 inches) on each side, but other bleed sizes may be required depending on the project and the printer. Information about bleed requirements is usually easy to find by contacting your printer or by looking on their website.

Exporting with bleeds
in Adobe InDesign 

• File > Export > In the Format drop down menu chose Adobe PDF (print) > Save > the Export Adobe PDF dialog box will appear.

• In the Marks and Bleed section, turn on Crop Marks and Bleed Marks. In the Bleed and Slug area, turn on Use Document Bleed Settings. This will use the bleed settings you inputted during document setup. Export.

Important safety tip:

You should take the bleed into account when planning out your composition so that important elements don’t run too close to the edge. Having to improvise a bleed last minute can lead to awkwardly cropped images.