Expert: LizaL - 12/21/2004

Question
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Followup To
Question -
Hi Lizal,

Thanks for that information. I will be very helpfull.I can redefine my problem. i keep my resulation in Photoshop at 300 pixels/cm i can not find where to get the dpi measurement. I do call the printers and they always say 300dpi. Most off my ads are A4 and around 3 to 5 MB at the moment.
i have found that using Illustrator helps in file reduction  off file size. A second point is i tend to have to drop a lot off images and logos into all ads so reduceing the number off layers could be a bit difficult. Maybe you might have some points that could help me.
Tanks in advance.

Answer
Hi Barry,

Thanks for posting the additional information! That always helps.

-- One thing I realize now is that you're going to the right place in Photoshop to change and check your resolution. It's just that you're using the pixels per centimeter option, as opposed to the pixels per inch. That's actually a pop-up menu, and if you click on it, you can change your measurement to inches, rather than centimeters.

Check out this screen shot and see if it makes it clear; I've circled in red what you'll see if you click and hold on the pop-up menu:

http://little-works.com/all_experts/dpi.gif


-- You also mentioned layers, and they will definitely increase your file size! When you're working on an ad, if I were you I would save the file as a regular Photoshop file, with layers. That way if you need to go back and make changes, you'll have the file intact, and can change any individual layer if you need to.

Then I'd save the file as a TIFF file, if it's going to be printed in a newspaper or magazine. Ask your printer about this first, of course -- but if TIFF format is OK, I'd use that.

When you save your file as a TIFF, you'll get a dialog box asking if you want to use compression. You can say no, of course, but that won't reduce your file size. If you decide to compress, use LZW as your choice, as I've shown here:

http://little-works.com/all_experts/tiff.gif


This method of compression is good because it retains the most information in your file, without adding to the size.


-- Try not to save as an EPS unless you've been instructed by the printer to do so, or unless you're using the file in a page layout program like Quark or InDesign. When you use an EPS in those types of program, the EPS can be embedded into the document, and it will go through a form of file compression there. But EPS is still a large file format, so try to stay away from it.


Anyway, I hope this added info helps, and please let me know if anything's not clear, or you need more help.

Lisa