Printing & Design Tips: FEBRUARY 2008, #79

Preparing Files for the Printer

Here are a few last-minute items to remember when preparing document files to send to your printer.


It is very easy to forget to change the color space of the photographic images in your document. In most cases you start with an RGB JPEG image. Either you have downloaded the image from the Internet, or you have brought it into your computer from your digital camera. Or perhaps you have scanned the image or brought the image into your layout program from a photo CD. In any of these cases, you may be working with an RGB JPEG without really thinking about it.

Your offset print provider, however, will need to have the image you submit be a CMYK TIFF (less likely to lose image quality than a JPEG). Changing color spaces from RGB (a light-based color space used for video monitors, the Internet, etc.) to CMYK (an ink-based color space used for offset printing) can alter the colors in your images. Therefore, to avoid surprises, it is better for you to make this color conversion before placing the images in your layout and submitting the final version of your art file.

Resolution of Placed Images

Remember to provide images with adequate resolution. The rule of thumb is to double the printer’s line screen at 100 percent of size. That would mean 300 dpi photo resolution at 100 percent of size for a print job that will use 150-line halftone screens.

Using a 72 dpi image from the Internet may look fine on your computer monitor, but the final printed product will look blurry. In addition, taking this 72 dpi image and upsampling (also known as interpolating) it to 300 dpi will also provide you with a blurred image. To be safe, scan the image at 300 dpi at the size you will need it in the final layout.

Another good rule of thumb is to make any modifications to the image in the photo-editing program before you place the image in the layout file. If you rotate the image, do it in Photoshop before you place it in Quark or InDesign. As noted before, enlarging the image is a bad idea, but reducing it is ok, and you should do this in Photoshop before placing the image in the layout file.

A Mock-Up Is Worth a Thousand Words

Give your printer a mock-up of the final printed piece. Nothing communicates what you expect better than a sample.

This goes for duotones as well. Get a sample from another publication, cut it out, and submit it. Tell the printer it is the target, the prototype of what you want.

It doesn’t hurt to clip a sample of the unprinted press sheet, showing weight, finish, and coating, to your mock-up, as well as PMS chips showing any match colors. Also, note what colors you will build (process inks).

Write notes to your printer on the mock-up, noting placement of dull or gloss varnishes, where the process color will go (are the photos 4-color, duotones, or black and white), where any tinted varnishes will go, etc. Specify whether you want a flood or spot application of aqueous coating, varnish, UV coating, or film or liquid lamination. Don’t forget to knock out areas that will need to accept ink (either hand-written areas on reply cards or areas receiving ink-jetted address information).

Note any heavy ink coverage, explaining how it will be handled (a single hit of ink, a double hit, or a tinted under-color application).

If undersize pages (short pages) will be included in the final printed piece, include these, to size, in the mock-up. And note any special finishing techniques, such as die-cutting, perforating, special folds like gatefolds, or embossing.

As you create this mock-up, you will probably see additional elements you will want to either note or actually include as a physical sample. The more closely your mock-up and accompanying notes match your vision of the final printed piece, the better. Don’t assume the printer knows what you want. Show him, and you will be happier with the result.

As a final note, it is prudent to create this mock-up early in the process. Discuss it with your printer, in person. Also, discuss distribution issues with your printer at this time. Problems may arise that you’ll want to address (such as what adjustments to your printed piece may be necessary to ensure its mailability at the greatest postal discount). The earlier you discuss all variables, the less chance there will be for a mistake or a panicked race to make last minute corrections before submitting the files.

[Steven Waxman is a printing consultant. He teaches corporations how to save money buying printing, brokers printing services, and teaches prepress techniques. Steven has been in the printing industry for thirty-three years working as a writer, editor, print buyer, photographer, graphic designer, art director, and production manager.]