Basic File Specifications for Large Format Printing

Large Format Printing File Set up

Large and grand format printing projects have a few rules that differ from printing smaller paper items such as business cards, this is due to the wide range of mediums and finishing techniques involved. Always check with your print vendor to make sure you’re using the correct specifications or in many cases, the design template appropriate for your project. With that in mind here are some basic rules to follow and the reasons behind them.

Set up the layout to your final print size whenever possible or use a simple scale such as half or quarter size if necessary. With large format printing a scale may be required as many graphic design programs and the PDF file format have maximum page or art board dimensions. Make sure you tell your vendor if you built your file to scale. Confirm the final dimensions and note them in the file name.

If you already have a layout and are looking to scale it up, it’s best to keep the enlargement in proportion to the original size. Stretching artwork and text in one dimension to fit often has a negative effect on the legibility of fonts and is especially awkward when stretching photos of people and animals.

Example: You have an 8.5″x11″ file at 300dpi and want a 24″x36″ poster

If the 24″ width is the critical dimension:
Width: 24 divided by 8.5 = 2.824 – you are enlarging your file 2.824 times
Height: 11 multiplied by 2.824 = 31.06
Resolution: 300 divided by 2.824 = 106.23

If the 36″ height is the critical dimension:
Height: 36 divided by 11 = 3.273
Width: 8.5 multiplied by 3.273 = 27.82
Resolution: 300 divided by 3.273 = 91.66

Proportionally you could produce a 24″x31″ or 27.82″x36″ poster with ideal resolution values.
This example was assuming one image with a resolution of 300dpi, if you’re working with a layout program with a few different images in place, all of your linked images must be able to enlarge at the same rate of enlargement and meet the minimum resolution requirements.

When printing your large format project, a minimum of 1/4″ bleed is required to ensure that your image is finished properly with color or graphics that go right to the trim or fold without leaving a sliver of white along the edge. In reality, cutting off a sliver of media is rarely possible, better to give your vendor a margin of error in case there’s a misalignment while printing, folding or cutting. If .25″ isn’t available in the image, consult your customer service representative for options.

Products that include hardware require more bleed for various reasons, make sure you check with your vendor, and get a template for file set up when it’s available.

Set up your design and extend the background color or any graphics along the trim edge of your project past the trim into the bleed area. See below for a visual guide. Do not put rules or borders on the document edge.

Keeping critical content such as text and logos away from the trim or finished edge is important because you never want them to be trimmed off, sewn over, or disappear into hardware once installed.

Projects such as banners with sewn edges, grommets and pole pockets have a slightly different rule, you should keep a 2” margin inside the trim edges to avoid hem stitching and grommets You’ll also want to keep everything 1” from the pocket’s stitching. Any graphics printed on the pole pocket area will be distorted by the pole inside the pocket.

Products that include hardware have larger margins or safe area to avoid losing or obscuring critical graphic elements due to the hardware, make sure you check with your vendor, and get a template for file set up.

Large Format Printing File Set up

In large format printing, viewing distance is measured in feet rather than inches, the eye won’t see blurry and jagged edges the further away the viewer is from the product. This is why an effective resolution of 72-100dpi is typically acceptable. The resolution can be higher, however resolutions lower than 72 dpi should be called out to your printer, they may have recommendations on how to improve the image quality. In very large prints or on textured media, it will be less critical.

If you built your design to half scale the image resolution in your layout should be double the ideal dpi and 4 times larger if at quarter scale. When images are scaled up at your print vendor your resolution (dpi) drops in proportion to enlargement.

1-10 ft
30 ft
>50 ft

1-3m
10m
>15m

100+ DPI
85 DPI
72 DPI

Tip: Review your image quality at the printed size in your graphic program (i.e., view at 100% or if it’s half scale 200%). Is the quality you’re seeing on screen acceptable? If not, it may be best to use a different image or reduce the size of your image for better results. You can also ask your vendor if they can help you improve it with sharpening or running it through a fractals generation program for better enlargement results. We do not recommend that you force a higher resolution on an image in Photoshop, the results may not be acceptable.

Image Resolution Examples

Tip: Watch for bad clipping paths, your high quality image may print well, however if you haven’t clipped the object out of the background properly, the edges could be very jagged or you could be missing parts of your image.

Tip: Avoid saving your high resolution files too many times as a JPG, this file format may compress your file with each save and has a tendency to leave JPG artifacts around the objects in the image that appear as a dirty halo or strange groups of bright green or pink pixels. It’s better to save your files as a TIFF or PSD until you’re done with all image manipulation then you can save a JPG if you need a much smaller file size.

Digital or offset printing machines use CMYK (cyan, magenta, yellow and black) pigments or inks to produce your print. Your electronic devices use RGB (Red, Green, Blue) which is capable of creating millions of vibrant colors that can not be replicated by the much darker pigments of CMYK. This is one reason this issue varies from vendor to vendor, some vendors are seeking to minimize the risk of unacceptable color shifts without having to adjust your file and reprint.

If your vendor doesn’t have a requirement, here is a tip. We recommend keeping your graphics or photos in RGB when printing photography such as landscapes and dramatic images. The RGB color space has a few benefits and you may prefer to work with them. RGB has a larger gamut of possible colors in the file and by keeping them you are not minimizing the range of color at the printer. Some digital printing machines include some bright inks like Orange and Red to accommodate some of the more vivid colors that traditional CMYK has difficulty matching. Secondly, RGB file sizes are much smaller and easier to work with at large and grand format sizes, which means faster processing at the design and printing stages. Some color shifts can occur in he conversion to print, but if the color saturation is the priority, it should be acceptable.

In critical color reproduction such as artwork or product printing where color matching is the priority, use a CMYK color space. Printed proofs that will be color corrected will be much more predictably manipulated in CMYK, as the black channel is critical to the final product. In an RGB image, you cannot correct the black ink channel.

Note: Beware of mixing the two color spaces, especially if you’re using transparent backgrounds or shadow effects on RGB images and placing them on CMYK or PMS spot color backgrounds. This will result in an oddly colored box surrounding the image with conflicting color spaces, it wont appear this way on screen but your vendor may see it at the printer.

RGB color shift

The Pantone Matching System is an excellent way to get accurate color, especially for brand specific color used in your logo. PMS colors should be called out to your vendor at the time you order, be sure to specify if you want to match the Coated or Uncoated book. Large format printing is a digital process, which means PMS inks won’t be used on the printer, however most vendors have a very reliable conversion from PMS to CMYK that gives you the best available color match. Make sure any Pantone colors are set to Spot color settings in your layout program.

Note: If your project is color critical and is not made up of PMS spot colors, a physical proof on the final media should be requested from your vendor to ensure that you will receive the color you expect.

Some print vendors may require you to convert your fonts to outlines or curves even when providing a PDF document. There are more than 200,000 font styles in existence and some of those fonts do not print well, or your vendor’s printing system doesn’t support it and will default the font to another style. If your vendor has this requirement you should convert your text to outlines, curves or paths, depending on how your layout program handles this. Once the text is converted to outlines, you can no longer make type edits as it’s now a graphic, be sure not to save over your original document.

Tip: If you’re ordering cut vinyl lettering, make sure you Unite the Paths, so you don’t have knockouts where your letters overlap. If your text was made bolder with a stroke, make sure your vendor knows where you want them to cut the letters, so they can convert your stroke to paths or walk you through the process.

Note: If your vendor handles any of your color correction, design or text changes, it’s best to give them all of your native files along with your links and fonts.

Every vendor will have their own set of rules for what they’ll accept. Here is a list of file kinds and when you should use them.

  • Press Quality PDF This will keep your photos and images in the original color space and resolution they were created with and embed your fonts. Be sure to include Cropmarks and Bleeds when saving your pdf.
  • High Quality PDF This will keep your photos and images in the original color space and downsample photos to 100 dpi, and embed your fonts. Be sure to include Cropmarks and Bleeds when saving your pdf.
  • PDF X1a This preset will convert your images to CMYK and embed your fonts. Be sure to include Cropmarks and Bleeds when saving your pdf.
  • Tiff with flattened layers including bleed in the overall image or canvas size

Provide your layout files if you’re depending on your vendor to adjust color, manipulate photo color or resolution or make text changes. Many print vendors will not support Quark Xpress, Corel Draw, or some of the freeware design programs, talk to your vendor about how to handle these.

  • Indesign: Packaged Indd with fonts and links included separately
  • Illustrator: Packaged Ai with links and fonts included separately, also provide a PDF of the layout with the “Illustrator default” preset with “Preserve Illustrator Editing Capabilities” is turned on. Indesign Packaged Indd with fonts and links included separately
  • Photoshop: PSD or Tiff with layers included and fonts provided separately
  • EPS: While this file kind is printable, it is usually an extremely large file size, when working in large and grand format sizes this may cause processing issues. EPS is generally considered outdated.
  • JPG or JPEG: These files often compress file data to make the files smaller depending on the quality level you used to save the file. The difficulty with JPGs is the more you open a file, manipulate it and resave, the more compression is added with each resaving which leads to loss of image quality. If that happens, we can see “JPG artifacts” start to form in areas where dark and light colors meet, these can be blocks of mismatched color that halo an image. At large format sizes these result in muddy and unacceptable prints.
  • PNG: This file format is intended for screen viewing and website use, so it’s often not large enough for printing large format, lastly the format can not be saved as CMYK which your vendor may require.
  • GIF this file format doesn’t support the correct sizes or quality for large format printing.

When designing for large or grand format printing, you must take into consideration the distance between viewer and the printed product. With that in mind the most successful large format designs use simple, bold and highly contrasting graphics, keeping both images and text large enough to be legible by your reader. To test if your project will be legible from a distance, position yourself 5-10 feet away from your monitor, if you can read everything, and the important message grabs the eye, you’ve been successful. Try it with the example below.

Large Format Design Tips

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