Acceptable File Formats for
Placed Images
TIFF and EPS are good.
TIFF
TIFF, short for "Tagged Image File Format" is the file format of choice for almost all raster (Photoshop) images. Use TIFF for your CMYK, greyscale, and bitmap (1-bit) files. There are 2 quirks to the TIFF format that are important to remember:
- Do not use the LZW compression option; it causes headaches such as crashed RIPs and inexplicable print failures at the film house.
- Remember to delete any unused channels, created when you save selections, before submitting your files for film output.
EPS
EPS stands for "Encapsulated Postscript." It's the standard format for vector graphics, such as those created by Adobe Illustrator and Macromedia Freehand. EPS can also be used for raster images, but only as necessary; it's not the most efficient format for delivering raster information, and will result in slow print times. You should use EPS format for raster images only if you need a duotone, a clipping path, or a transfer function. Otherwise, TIFF is preferred.
When saving EPS files out of either Illustrator or Photoshop, you're presented with a bewildering array of options. Ignore them: the defaults work, so don't touch anything and you'll be fine. [In particular, do not select JPEG compression for your EPS files]
Please do not embed raster images within Illustrator EPS files - this almost always causes problems down the road. It's a much better idea to link to the raster images from your page layout software. If you need to embed a file for whatever reason, make sure that you supply a freestanding copy of the embedded graphic, so that we can inspect and manipulate it as necessary.
Everything else is bad.
Native Files
Adobe has chosen to include a dubious "feature" in InDesign and Illustrator: importation of native Photoshop files. In some ways, placing a native Photoshop file in your InDesign layout is more convenient for you, the designer, since you don't have to resave a new TIFF copy from your working files each time you make a tiny change. When it comes time for you to submit your files to us, though, please don't submit a collection of native Photoshop files with 20 layers each - please give us TIFF and EPS files instead. Keep copies of your working files as part of your backup routine.
DCS
DCS, short for Desktop Color Separation, is an extension of the EPS file format, authored by Quark. There is only one instance where DCS files are necessary, and that's when you have a raster image that has to contain a spot color channel in addition to the CMYK channels. We would prefer that you use DCS files only for this purpose, as the format is buggy and unwieldy.
JPEG
The JPEG algorithm for image compression is an amazing thing; Even at maximum quality settings, it can create incredibly small files with minimal degradation to the image. However, there is always some degradation, and in the world of printing, there's no reason to settle for anything less than the highest quality. We don't want them. If you get a JPEG from a stock photography house, resave it as a TIFF before you submit it.
GIF
GIF is a web-optimized format that's inappropriate for print. It's limited to 8-bit color and has LZW compression built in. Do not use.
PICT, BMP, WMF, PNG etc.
They all have their place, but it isn't here. Do not use. |
