Sneaky Dirty QUICK way to address greyscale color shifts with a bonus feature

[jtiii]

If you can't generate your own icc profiles, your greyscale image has a tint, and people are going to be viewing the graphic from more than a couple feet away -
Turn your image into a halftoned print (like a newspaper photo)

Open your raster file in Photoshop (if vector then first export the grey portions as a raster file)
Image-Mode-Bitmap
Output Resolution-Depends on how far viewers will be, figger it out
Method-Halftone Screen
Frequency-Again depends on viewing distance and what output resolution you picked earlier
Angle-Whatever (I use 22 degrees)
Shape-Round

That's it! Drop it back in your drawing program if mixing with vectors and output it from there.
For small stuff i.e. photos less than 2sq ft I use 600dpi and 50lpi

BONUS - your image won't shift colors as the various inks fade at different rates!
Edited for clarity and to add pictures to the explanation

 

[jtiii]

I'm missing how this works? I mean, what is photoshop doing to fix the grey tint?

Instead of greys, it's all black and white! (like a pic in a newspaper)

 

[jtiii]

Wouldn't exporting as a black/white image do the same thing?

Not sure what program you're exporting from, but Photoshop is the only program I know that gives good halftone options and results.

 

[ColorCrest]

If you can't generate your own icc profiles, your greyscale image has a tint,

Are you aware that color printers can be calibrated and since they're calibrated to produce neutral gray scales, maybe that would make things easier?

 

[unclebun]

I'm missing how this works? I mean, what is photoshop doing to fix the grey tint?

It's replacing the gray with halftoned black.

 

[Saturn]

Maybe an even trickier trick would be to save it from Photoshop as a greyscale Tiff, then when you drop it into a CMYK Illustrator file you can adjust the grey appearance as you see fit?

Rather than being just 100K or some mixture of a default rich black (75/68/67/90), you can define the specific CMYK color build of that Tiff warmer or cooler or less density as you see fit, maybe 35/25/15/100 looks better AND saves a little ink. ;p

Obviously easiest to manage on straight one-image greyscale stuff.

 

[jtiii]

Are you aware that color printers can be calibrated and since they're calibrated to produce neutral gray scales, maybe that would make things easier?

Thank you for that helpful and not at all snarky reply! If you google search this site like so site:signs101.com grayscale tint You will find about 50 posts, most of which are from people struggling to get their grays gray. I have an HP 315, am using the right profile, and even after running calibration my grayscale photo looked yellow. Instead of tweaking color settings, reprinting, and tweaking some more, in less than a minute I am guaranteed to have a true greyscale.

I know various RIPs have various ways of addressing this issue, but I posted this because it works regardless of which printer you have, and regardless of which printer you use.

 

[jtiii]

Maybe an even trickier trick would be to save it from Photoshop as a greyscale Tiff, then when you drop it into a CMYK Illustrator file you can adjust the grey appearance as you see fit?

Rather than being just 100K or some mixture of a default rich black (75/68/67/90), you can define the specific CMYK color build of that Tiff warmer or cooler or less density as you see fit, maybe 35/25/15/100 looks better AND saves a little ink. ;p

Obviously easiest to manage on straight one-image greyscale stuff.

That definitely makes sense if you want to warm or cool your picture. This is just a quick way to insure that your image is truly neutral regardless of your printer or RIP.

 

[jtiii]

I'm missing how this works? I mean, what is photoshop doing to fix the grey tint?

Yeah I never actually mentioned what I was doing (making halftones)! Sorry about that - I added some pics up top that should make it much clearer.

 

[Boudica]

I can't wait for someone to try this and report the results. I'm to busy right now to experiment.

 

[jtiii]

I can't wait for someone to try this and report the results. I'm to busy right now to experiment.

Didn't you like my pretty pictures?

 

[Johnny Best]

Thanks for the tip, will try it out.

 

[Saturn]

I was overthinking my last suggestion as I wanted to emphasize the ability to tweak the channels easily, but can't you skip the conversion to bitmap altogether if you use a greyscale tiff and place it into a CMYK Illustrator file? This is what I do.

You can triple-check things by looking at the output separation of your PDF in Acrobat and verifying that only the black channel has the 100k info you want.

 

[jtiii]

I was overthinking my last suggestion as I wanted to emphasize the ability to tweak the channels easily, but can't you skip the conversion to bitmap altogether if you use a greyscale tiff and place it into a CMYK Illustrator file? This is what I do.

You can triple-check things by looking at the output separation of your PDF in Acrobat and verifying that only the black channel has the 100k info you want.

Saturn, that looks really interesting and useful - I don't have illustrator (or acrobat) and am not sure how to do that in CorelDraw, but I'm gonna dig a little!

 

[Saturn]

Wish I knew more about Corel! I think the key is that it's a greyscale TIFF. Jpg or other formats will not work as far as I now. You also can't do it in an RGB document, so make sure it's CMYK when you start, before you place anything.

I get a lot of B/W images from folks that "look" greyscale but aren't. So it's always worth checking that it's truly desaturated or saved as greyscale (had the color data removed), since we all know it doesn't take much to lean into looking greenish or reddish.

Yeah having the ability to double check the channels in Acrobat is really nice until it becomes second nature. Maybe that's something you can verify in the RIP too?

 

[ColorCrest]

There is the Rube Goldberg Challenge event every year.

Just a thought.

 

[Pauly]

I'm not sure if people understand that OP is turning B&W images with grey tones into a halftone pattern with only black dots.
When you print the image. the printer will only print solid 100% black (not black ink, but 100/100/100/100 or 95/90/85/90 or how ever your cmyk output is for 100% black) for the black dots, no matter how big or small they are.

Does it work? Yes it does!

 

[StephenOrange]

I get that the OP has this tip that helps him out, but this is a crummy plaster solution to a much bigger problem on so many printers, with operaters not caring to get educated on how to fix the problem. Again, not dissing the OP, but this is not moving a the problem towards a good, sustainable solution.

What if the file is being viewed close up? What if the image contains grey areas within a larger colour image? What if it’s an actual logo? What if you’ve been supplied a massive flattened image?

Rather put time and money into sorting out your profiles. If he is running a 315 then the profile is very possibly not correct for the media (remember that white comes in many colours) so you might be thinking a profile for a white cast is fine for a cheap promo white vinyl. But it’s not. Cheap vinyls have been whitened to within an inch of their usability with OB’s. HP actually ships with really good profiles, so I doubt it’s their profile that has the issue.

Check if the light colors are holding up during printing. The light colours on latex machine have been historically shitty and that side of the head would fail way before the others.

The biggest issue I have with this tip is that if your greys are out, then your whole image is very possibly out. Greys are the first thing I look at after doing a profile. How is this solution fixing all your other colours?
I’m willing to help you create a proper profile, just keep in mind that I am based in South Africa, so sending printed swatches will take a while.

 

[StephenOrange]

I'm not sure if people understand that OP is turning B&W images with grey tones into a halftone pattern with only black dots.
When you print the image. the printer will only print solid 100% black (not black ink, but 100/100/100/100 or 95/90/85/90 or how ever your cmyk output is for 100% black) for the black dots, no matter how big or small they are.

Does it work? Yes it does!

I get the solution, and have used this in artistic settings, but this isn’t a sustainable colour management tool at all. It’s teaching more people to ignore the bigger issue that they possibly don’t even know they have.

 

[Pauly]

I get the solution, and have used this in artistic settings, but this isn’t a sustainable colour management tool at all. It’s teaching more people to ignore the bigger issue that they possibly don’t even know they have.

I Agree, a lot of people don't understand the concept of colour management, or know that they should be creating their own media profiles.

But, as OP said "Dirty way to..." people should understand the heading.