During the 4by6 printing and finishing process, it is normal for there to be slight variances when cards are trimmed to their final size. Therefore, you should add ‘bleed’ to your artwork when there are elements that reach the edge of the card.
The Bleed Area should extend past the trim dimensions by .125″ on all four sides. For example, 4×6″ postcard art with Bleed Area has a final image area of 4.25×6.25″. Many design applications provide options for setting the bleeds of your document separately, and you’ll need to specify that you want to include bleeds when you save your PDFs.
If you are working in an image application like Photoshop, you should set your document size so that it includes the Bleed Area.The Safe Area is used to describe an area .125″ within the trim on all four sides. This is the area where it is safe to place critical design elements like logos and text that you don’t want to appear too close to the edge of the card when finished.
When uploading your artwork to your order, you will see a preview that displays your artwork within the Bleed and Safe Areas.