Gray... ugh....

[Bigdawg]

I use VersaWorks for printing everything. When I want to nail certain colors I use the VersaWorks swatches and let the RIP do a switchout when it prints. Great for Illustrator files...

The design I'm having trouble with is an offwhite gradient to a light gray. The full piece is Photoshop - no way to recreate in Illustrator. I can print a beautiful gray that looks fantastic under my flourescent lights... but is a not-so-beuatiful green outdoors. All my other color are hitting where they should be.

I adjust some of the blue out of the gray so it appears slightly red tinted when I print... but looks better (not great) in the sun... much closer to the neutral gray I want. This is not a good method and is very hit and miss as to what colors I want. (I have spent years working with high-end color, so I can almost "see" the colors I should be getting for any CMYK combination.

Any recommendations or help? I have tried using the 3M profile straight from them, using the 3M profile we created internally and just for kicks and giggles, I used a generic cast profile. Pretty much same results in all of them for the gray. (Our 3M profile is accurate on all the other colors though - besides the gray)

 

[Ponto]

I've printed out a few pages titled "Grayscale Printing" which I found in the Knowledge Base section of the Roland Website... sorry, I don't have a link but a search should yield the same results ...hope this helps.

JP

 

[Bigdawg]

Will absolutely look. Thanks JP!

 

[cgsigns_jamie]

If the image is completely grayscale use the "Density Control Only" option for your Color Management Preset. This will prevent the rip from adding in other colors and will only use the black ink cartridge.

 

[Tovis]

Don't you love using color theory... If you make a global correction in photoshop to neutralize the gray does it throw off all the other colors?

 

[SignBurst PCs]

I am not color expert, but I think that "custom profiling" would help with this issue.

I have also seen customers adjust the "yellow" out of the gray (to get rid of the green tint) with good results.

 

[Bigdawg]

I have a custom profile...

And the image is full color with gray in it... so can't use the density control

Tovis - I have the gray on a seperate layer so I can do what I want with it. There is an overlaying photo that blends into the gray background. Photo and type are all fine. It's just that damn gray! I've tried RGB and CMYK with different results, but none acceptable.

 

[Gino]

Quite often our greys turn out on the greenish side also. It's very frustrating, but we've created a few 'custom' greys as we did for metallic gold. I guess when you're trying to match a color, it gets even harder. I always say.... Jeremy, figure this out.... and fast.

The only thing I can think of is.... can you utilize only the black channel and leave CMY out of it ??

 

[Tovis]

Have you tried:

To adjust for global, if too blue add yellow
To adjust for global, if too red add cyan
To adjust for global, if too green add magenta
To adjust for global, if too yellow subtract yellow
To adjust for global, if too cyan subtract cyan
To adjust for global, if too magenta subtract magenta

For a local correction to your gradient you could probably just do a layer color adjustment. Or can you redo the gradient with target colors you know are a non-biased gray?

Can you print just the layer, also what rendering intent are you using in the rip.

 

[Tovis]

Can you attach the file or a screenshot?

 

[javila]

I've read that proper way to deal with a grayscale with color image is to build a pdf so the RIP can manipulate and color process each "section" of the file independently.

 

[Bigdawg]

Yep.. have been making global adjustments to the gray.. it is a solid block under the faded photo... swatch attached. Glad you posted that Tovis - many people have no idea how to adjust using subtractive instead of adding color.

I expect the banding in the gradient - not enough color steps in the two colors - but I have GOT to get a fairly neutral gray on the rest.

EDITED TO ADD: I am having to match layout to previous wraps that were done by someone else... so I have no variance in colors or layout (in other words, don't blame the smushed type on me LOL)

 

[Tovis]

Where is the problematic area again?

 

[Bigdawg]

right side... gray area

 

[Rooster]

What you're experiencing is called metamarism. The colors appear different under different light sources. The easiest way to cure this to to rebuild the existing profile to use less GCR. This will build your neutral using more black than cmy to make up the neutral colors.

I had the same thing doing a 4x8' RGB black and white print. Looked great under the daylight florescents, but turned a greenish shade under natural sunlight. I called up the data from the original targets and rebuilt the profile where the black generation curve had a 45 angle from 0-100 and it eliminated 98% of the color shift.

You may see a little more graininess in the highlight areas than usual since the black dots are much more visible than the CMY, but the reduction in metamarism will be worth it.

 

[Bigdawg]

and the best part is that I understood all of that Rooster... thanks... I'll give it a go.

 

[Graphics2u]

What you're experiencing is called metamarism. The colors appear different under different light sources. The easiest way to cure this to to rebuild the existing profile to use less GCR. This will build your neutral using more black than cmy to make up the neutral colors.

I had the same thing doing a 4x8' RGB black and white print. Looked great under the daylight florescents, but turned a greenish shade under natural sunlight. I called up the data from the original targets and rebuilt the profile where the black generation curve had a 45 angle from 0-100 and it eliminated 98% of the color shift.

You may see a little more graininess in the highlight areas than usual since the black dots are much more visible than the CMY, but the reduction in metamarism will be worth it.

Thanks for that explanation! That'll be very good to know.

 

[bbeens]

+1 for Rooster's comment. Depending on the profiling package you have you may have few, maybe no options to adjust UCR/GCR. In the nicer packages you can tweak quite a bit. For the cheap and quick fix, if possible try different media. Different coatings, OBAs, etc can affect metamerism.

Bryan

 

[Bigdawg]

Got to be 3M 180IJ v3... but I have an i1 package and as soon as the job I've got running is done, I'm going to see what I can do. Will update...

 

[cptcorn]

What you're experiencing is called metamarism. The colors appear different under different light sources. The easiest way to cure this to to rebuild the existing profile to use less GCR. This will build your neutral using more black than cmy to make up the neutral colors.

I had the same thing doing a 4x8' RGB black and white print. Looked great under the daylight florescents, but turned a greenish shade under natural sunlight. I called up the data from the original targets and rebuilt the profile where the black generation curve had a 45 angle from 0-100 and it eliminated 98% of the color shift.

You may see a little more graininess in the highlight areas than usual since the black dots are much more visible than the CMY, but the reduction in metamarism will be worth it.

GCR is key to this problem along with having a good profile.

Got to be 3M 180IJ v3... but I have an i1 package and as soon as the job I've got running is done, I'm going to see what I can do. Will update...

I recreate my profiles every other month as the weather changes... Sometimes I just relinerize and sometimes I start over from scratch. Everything adjust the print, temp, wind, position of the moon, solar flares, supernovas, ink drops, who's president.