Understanding Print Specifications: A Guide to DPI, Color Modes, & File Formats

To get the best possible results from your commercial print jobs, you need to understand the basics of print specifications. These are the file formatting and quality standards your commercial printer sets to ensure sharp, saturated, and polished prints. Of course, a quality print partner like Wallace Carlson will do what they can to call out potential problems before your job goes to press. But, by understanding the specifications yourself, you can help ensure nothing slips through the cracks while you are preparing your files, ensuring costly reprints are never required.

DPI & Resolution: Why It Matters

DPI stands for dots per inch. DPI is used to measure the resolution of a printed images, with higher DPI equating to higher-resolution results. If the DPI of a file is too low, the printed image may appear blurry or pixelated. The industry standard minimum for commercial printing is 300 DPI.

Color Modes: CMYK vs. RGB

CMYK stands for cyan, magenta, yellow, and key (black). It is the preferred color mode for commercial print files, because it creates the most color-accurate prints. Digital files often default to RGB (red, green, blue) for their color mode, which is optimized for digital displays that use light and pixels to produce images. In these cases, the color mode of the file should be switched to CMYK before being sent off, to ensure color accuracy.

Bleeds, Margins, & Safe Zones

Bleeds and margins are print design elements necessary for ensuring your print content is neither cut off nor incorrectly framed. We cover this topic in depth in our blog post How to Design For Margins and Gutters in Printing. Briefly, here are the minimum specifications to keep in mind for these design elements:

• Your design file should include a minimum bleed of .125” past the trim line if any color or design elements are intended to extend fully to the edge of the page. 
• Your design should include adequate margins to ensure the content is easily understood, but not so large that the design looks unintentionally empty.
• Your design should include a safe zone of negative space between your critical content and the edge of the print, regardless of whether you’re using bleed or blank margins.

Vector vs. Raster Graphics

There are two types of files used in commercial printing - raster and vector. Raster files are used for designs with photography and complex illustrations, and should generally be formatted as TIFF (Tagged Image File Format). On the other hand, vector files are used for designs with solid colors like logos, simple illustrations, and charts. Commercial printers accept a few different file formats for vector designs, particularly PDF, EPS, and AI files.

Less data-rich file formats, such as JPG or DOC, are commonly used for at-home printing, but are not suitable for commercial printing. This is because the data they contain is typically insufficient to produce professional results.

Finally, one extra, critical step for design files with text is font embedding. Embedding ensures that the correct fonts are always generated, even after the file is sent to your commercial printer for printing. Without embedding, different systems may interpret your font data differently, possibly reflowing the text or even replacing it with a different font.

When in Doubt, Reach Out

With these basic guidelines in mind, anyone can set the specifications for their commercial print files. However, we know that sometimes what seems simple at the outset gets a lot more complicated once you’re staring down a bunch of Adobe InDesign menus. So, if you ever find yourself uncertain about which settings to choose or whether your file is ready to print, don’t hesitate to reach out.