Its so nice to have a place where professionals come to discuss these things.

I have a photo that I am printing on top of a rich black 40c 30m 20y 100k.  At one side, the photo should fade out.  I originally did this by applying a transparent to rich black gradient, however when we got the print back the colors seem to desaturate as well.  Is there any way to do this without having that effect?  When I try and think about it theoretically, I have to say no, but since I'm sure I've seen this effect (although I'm not sure if the black was rich) I keep trying to come up with something.

Thanks

Brian Carter

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Brian,

You probably already have this covered, but make sure you're multiplying whichever layer is on top, photo or gradation.

best,

Ed A

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Brian writes,

Yes, but there's an important warning first. If this job is going to press, and if this rich black covers a reasonably large area, the proof you got back is NOT going to match the press result at all. The presence of all that black ink near the picture will guarantee excessive black density in the image itself.

So, the image has to 1) be lighter than you would normally choose and 2) use UCR, nothing greater in the way of black generation. These comments apply ONLY if the destination is press. If you're going to some kind of inkjet or similar printer, forget them.

That said, this type of effect is easier to achieve in RGB or LAB than in CMYK because Photoshop doesn't account for black ink in certain calculations. So,

1) Start with a reasonably correct RGB picture. Expand the canvas size and fill the blank area with 20r20g20b, NOT a pure black. So, you now have a picture that butts a black surrounding area, but no vignette effect.

2) Put a blank layer on top and fill it completely with 20r20g20b, obliterating the image underneath.

3) Layer: Add Layer Mask>Hide All. Now you the the picture underneath again.

4) Create the vignette effect on the layer mask by fading or airbrushing parts of it to something lighter than black, first having deselected almost all of the interior of the image. This will show the soft edge but also the desaturation that you have been complaining about as the image fades into the background.

5) Change layer mode to Luminosity. This will restore the color feel.

6) Flatten Image and convert to CMYK, being sure (if the job is going to press) to choose a Custom CMYK>UCR, not any type of GCR.

7) With Select>Color Range, grab the black background and by adjusting the Fuzziness setting, capture a slight amount of the edge as the picture fades in. If anything in the interior of the picture gets selected, deselect it.

8) Apply curves to the selected area to change it to 40c30m30y100k or whatever.

Dan Margulis

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Ed Atkeson wrote:

Well, I was at one point, but that made the areas where it overlaped (rich) black in the photo darker then regular black and possibly over the ink limits.

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Dan,

Thank you so much for the walkthrough - a couple of follow up questions though.

1)This job IS going to press.  How much lighter should I make the image and am I correct in assuming I change the dot gain? I have PP if you want to give me a page number as this sounds familiar, but there's a lot of information in that book and everytime I think I found it-its dot gain.  

2) The image contains large shadow areas that butt up against the side I am vignetting.  When selecting the outside of the vignette and adjusting the curves, there is a very clear line of demarcation in the areas where the shadow butts the edge.  Would selecting via select>color range within a selection of the luminosity layer gradiation be a better way of selecting for something like that?

(4 "selections" in one sentence.  I think that's a record.)

Thanks again.

Brian

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Brian writes,

I would try taking whatever dot gain settings you have now and increasing CMY by three points each and black by eight points. Or you could do the same with curves. It's a real crapshoot. The one thing you know for sure is that normal color management won't work because no proof can possibly behave in the way the press is going to on this image. Designs like this are devoutly to be avoided.

Curves and hard-edged selections don't mix. I don't know where the selection needs to be made but it has to be soft-edged. You should be able to adjust the fuzziness setting in Select Color Range so that this doesn't occur. If the vignette has to begin somewhere in these shadows, so be it. Or perhaps the start of the vignette is too sudden. There are probably several different ways to attack the problem.

Dan Margulis

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Hi Brian,

On Friday, March 14, 2003, at 08:09 AM, Dan Margulis wrote:

I would try using "Blend if" to target the shadow areas of your image to help control where the gradation starts its transition. By using the dark areas of the image through Blend if you can further hid the de-saturation of the shadows.

On Thursday, March 13, 2003, at 07:32 AM, brianccarter2000 wrote:

I might also try using a rich black that was warmer. Something that is closer to the balance of the shadows of your image. Unless you are trying to match a rich black some where else in the project. In that case I would move the balance of the shadow in your image.

On Thursday, March 13, 2003, at 12:25 PM, Ed Atkeson wrote:

I agree with this. However. it can goofs up the dmax. Again, mess with the Blend if sliders to target the transition range.

I would suggest doing this work in CMYK because of the targeted rich black. Although it might look better when build in RGB, is it CMYK you have to contend with to get the rich black.

One last crazy idea:

Take your image and convert is twice. First with your regular conversion. Second with a heavy black generation setting. From there, use the heavy black separation to replace the shadows of the first conversion with Blend if. Then pick up the heavy black conversions darkest shadow as the callout for the rich black. You can always fudge the balance a bit to get it closer to what you need. You will have some additional work to clean up the image areas you want to stay saturated but at least your blacks will transition well together.

Good luck,

Alison Walker