Expert: Glen Demers - 9/11/2008

Question
Glen,
I am a prepress manager and we are trying to save server space. Currently we
save our .psd files with binary or ASCII previews. I have noticed that if we check
JPEG preview that that the file size is cut dramatically. Can high end RIPs handle
this file type and is there any image problems that will occur by using this
method.

Answer
Hi Chris,

I suspect you are actually saving your files as DCS 2.0 files. Photoshop will add a .eps extension to DCS files and allow you to specify preview options as well as encoding. The preview occupies a very small amount of memory relative to the file size and is important for placing and linking files in layout programs as well as previewing in Bridge or other catalogs. JPEG is a lossy compression scheme and if you use it, image degradation will result. Unless you really need to save in this format because of spot colors, etc, you would save space by saving them as Photoshop native files, Photoshop will add the .psd extension.
Saving originals as RGB instead of CMYK will save you 25% and if you put all your images in a folder and archive it using zip or Stuffit it should save an additional 50%.
Most RIP's can handle .psd, .tif, .jpg and .eps files but some balk if LZW compression is applied to images.

Hope this helps,
Glen Demers
Adobe Certified Expert, Photoshop 7
Prepress Technician, Best Printing Online
www.bestprintingonline.com

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