Expert: Glen Demers - 11/24/2009

Question
I read your response to "Improving Newspaper Reproduction".  Can you help me to create a profile with the dot gain of 30% or more?  I'm not sure exactly how to do this.

Also, when I create my pdf, is there something special I need to use? In Illustrator, I normally go to "save as" pdf and use the default settings.  

I'm not sure what you mean by keeping a 5% dot in the highlight areas.  Can you please explain that?

Normally I use the photo I took, adjust in photoshop- convert to grayscale and adjust the curves, contrast, levels, etc. and then open the image in illustrator, copy and paste the original into my illustrator ad.  Is this not the correct way to do this? The newspaper told me to make sure I highlight the ad first in illustrator and go to "edit colors" and choose grayscale. That still keeps my illustrator file at cmyk so I'm not sure how that helps.  I want to make sure it is in grayscale but don't know how other than by doing that.  

Please help!!


Answer
Hi Lauren,

Highlights are the lightest parts of your photo. When you measure them with your eyedropper in Photoshop you'll want a minimum reading of K = 5%. This excludes what are called specular highlights - flashes reflected in mirrors and bare light bulbs - these small areas are blown out anyway and a reading of 0% is expected.

Once the image looks good to you go to Edit>Convert to Profile... and select a grayscale profile, the defaults are Dot Gain 10%, 15%, 20%, 25% and 30%. The higher the number, the lighter your photo will print. Convert to profile will change the readings in your image but will not change the appearance of the image onscreen.

To make a custom profile go to Edit>Convert to Profile and choose Custom Dot Gain. A curve will come up. Dot gain is customarily adjusted only in the 50% box so 70% in the 50% box is a 20% dot gain. When you save your image do a "Save as..." and make sure embed profile is checked and that it is the profile you want.

DO NOT copy and paste into Illustrator, go to File>Place... and place your photo into your Illustrator file. When you copy and paste you're only getting the photo's preview in the Illustrator file. I would suggest you select all, deselect your photos and the go to Edit>Edit Colors>Convert to Grayscale. The photos you know are grayscale and this will convert everything else.

When you Save as... out of Illustrator, select format Adobe PDF and click save. In the next window select "High Quality Print" in the Adobe PDF Preset popup menu. This will make sure your PDF honors your profile settings.

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

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