A page bleed is a technique used to compensate for, or eliminate, mechanical problems when your project is being trimmed after printing. If the graphic element such as pictures, graphics, or background color is not carried beyond the edge of the page, there is the possibility that a small area of blank page will be seen at the edge after the page is trimmed.
When page elements, such as pictures, graphics or background, touch the document-page edge, they will need to be extended beyond the page. The amount to extend is called a page bleed. Typically a bleed will extend 1/8 in. (3.175mm or 9 points) beyond the edge of the page. Some professional page-layout programs allow for a value to be entered in the document setup. This page-bleed option allows the artist to specify which edge(s) of the page will require bleeds and at what measurement.
Page Setup
Adobe® InDesign® allows you to enter a Bleed amount when creating a New Document. You may have to click the More Options button on the menu to display the bleed options.
Adobe InDesign New Document example setup with Bleed values
Layout example with page bleed guides
However, most applications like QuarkXpress® and Microsoft® Office Publisher® allow for only page size and margin values. With these applications you will need to extend your page elements beyond the page edge without a quide.
Sample layout without bleeds or guides
Sample layout with bleeds pulled beyond the page edge, without guides
If an image, is cropped to the page edge, and there is enough image available, simply pull the crop box past the page edge to accommodate for the page bleed. The same is true for text boxes when they are used as graphic elements, such as a background design. As demonstrated in the examples below, Pull Bleed-Before and Pull Bleed-After, the size of the photo allows the background color to easily be extended with no visual loss or problem in the layout.
If your image is not large enough to extend beyond the page edge for a bleed, you can choose to move the image or graphic. Because this will alter the layout by decreasing the viewed size, this choice may need to be weighed with respect to the design integrity of the project, and preferably decided by the creator of the artwork rather than the commercial printer. In the example below, Bleed-Move - Before and Bleed-Move - After, you will see that because the butterfly is tightly cropped, part of the image will be lost after the bleed is pulled beyond the page edge.
In the example below, Bleed-Enlarge-Butterfly_Before and Bleed-Enlarge-After, the choice was made to enlarge the image to accommodate the bleed. Usually a 2% enlargement (102%) is adequate for a bleed. This choice, as in the above Move Image example, will change the design integrity of the project by creating a new crop point in the photograph. Since the choice of whether to move or enlarge the graphic element that is too tightly cropped will affect the design integrity of the project, the designer rather than the commercial printer should make this choice.
Similar to the Image Scaling description above, anamorphic scaling is the enlargement of only one dimension of the graphic element, either the height or width to accomodate the bleed. This type of scaling is considered a distortion but can be unnoticeable. As you can see in the example below, Anamorphic Bleed - Beach-Before and Anamorphic Bleed - Beach-After the width has been enlarged, but the height has remained the same.
If the graphic element is not large enough to be bled, but the area is a solid, a tint area, or has similar characteristics such as the example below with sky and undefined clouds, you may be able to use the step-and-repeat function in your layout program to create the additional bleed area. Do this by copy and pasting a duplicate image on top of the first, shifting the duplicate into the bleed area, and then sending the duplicated image to the background. Ideally, there is no visual integrity loss, as you can see in the examples below, Step-Repeat_Desert-Before and Step-Repeat_Desert-After.
If an image or graphic element has a similar or consistent color, than you can add an area of solid color to use for the bleed. Simply sample a common color with the Eye Dropper tool, or by using the Info palette and add this color to your swatch palette, extend the crop box of the image to accommodate the needed bleed area, and then fill the extended area with your newly selected color. Even though this isn’t a perfect situation, it is better to have a color on the edge, than to potentially have a visible white area once the printer has trimmed the printed piece.
Another more advanced technique to create a bleed area is to use the clone tool in most bitmap editing programs like Adobe Photoshop®. You will need to enlarge your canvas on the side that needs the bleed area added then using the clone tool, duplicate the pixels along the bleed edge. This technique is not the easiest, but as you can see in the examples below, Bleed_Clone-House_Before and Bleed_Clone-House_After the added area blends nicely.
As you can see from the above examples, some techniques for adding bleeds can alter the design layout of a project. In this case, the print client will either approve what the printer has altered or submit files to the printer with the necessary bleed area completed as he chooses. Most commercial printers routinely pull needed bleeds in print projects. This is a fairly simple adjustment if there is enough image area to accommodate this adjustment, so you may not receive any extra charges. However, for the more extensive work that we described above, you might receive an alteration charge that could be more than you expect. If you intend to make finished files for press-ready PDFs, or to submit your files to an offset printer without incurring alteration charges, than you will want to consider adjusting your own bleeds.
Return to the Page Setup menu for more page setup consideration topics.
