For example, for postcards you'll notice that the file that you are sending is actually 4.25" x 6.25" instead of 4" x 6". This extra space is what we call the bleed area. The bleed area is included to ensure that artwork gets printed to the edge - artwork gets printed with larger dimensions and is subsequently trimmed down. Although, backgrounds and graphics should be extended into the bleed area as shown with the background in the above example. Not having them extend into the bleed area could result in a white or unprinted border around the edge of the postcard.
Keep all text within the safe zone to make sure no important content is cut off.
ADDRESS BLOCK AND POSTAGE
On the postcard, there is a space marked off as RED: INK-FREE AREA. Anything in this area will not be printed to leave room for the postage and address information.