Cut vinyl match to CMYK

[Signed Out]

Trying to match a gray cut vinyl to a cmyk value. 55,46,46,11. Is there anyway to find out if there is a cut vinyl that is a very close match to this?

 

[Greenlight signs]

use a spectrometer to measure the color of the vinyl.

 

[unclebun]

Medium Marine Gray (Avery 950)

 

[Signed Out]

We don't have one. I guess I can print the color and try to match it to some gray vinyl swatches. Hopping there is a reference on this somewhere to save some time.

We are going to be making gray colored boards that are to be used as backgrounds for facial recognition software. They gave me this spec for the gray backgrounds:

"BACKGROUND The subject whose image is being captured shall be positioned in front of a background which is 18% gray with a plain smooth flat surface. A Kodak or other neutral gray card or densitometer shall be used to verify this 18% gray reflectance requirement

The exposure shall be keyed to the background. Several areas of the recorded 18% gray background shall be used to verify the proper exposure. The averages of the 8-bit Red, Green, and Blue (RGB) components within each area shall be calculated. Each of the RGB means shall fall between 105 and 125 with a standard deviation of plus or minus 10. Furthermore, for every area examined, the maximum difference between the means of any two of the RGB components shall not exceed 10."

So I asked if they happen to have a RGB/CMYK/Pantone? They gave me a CMYK so should be good there to just print the backgrounds. However we are going to be doing quite a lot of these, so would be much more efficient to just sheet some ACM with cut vinyl rather than print/lam/sheet.

 

[Signed Out]

Medium Marine Gray (Avery 950)

Cool, thanks I'll check it out. How did you come up with that?

 

[unclebun]

Cool, thanks I'll check it out. How did you come up with that?

I looked at your CMYK mix in Corel Draw and looked at a vinyl color chart to see which was closest. But just from experience I was guessing that was going to be the closest. However, I doubt that it will be a specific perfect match to 18% neutral gray if you have to meet those specs. Usually when photographers have to make 18% gray walls, etc., they paint the wall. There are standard formulas for making 18% gray paint, and there's even $80/qt paint that is premade to 18% gray.

 

[Billct2]

Good info unclebun...I did not know that and though I have yet to get a request for this I imagine it may come up the future

 

[ColorCrest]

So I asked if they happen to have a RGB/CMYK/Pantone? They gave me a CMYK so should be good there to just print the backgrounds. However we are going to be doing quite a lot of these, so would be much more efficient to just sheet some ACM with cut vinyl rather than print/lam/sheet.

No, the CMYK will not be good there. You were correct to ask for a Pantone ID as that system is designed to communicate a color. However, because they are being so specific, they should have provided you with an actual Kodak gray card. Also, (me being facetious) anyone in upstate New York should be able to grab a Kodak gray card from their back pocket. (Kodak, RIT, and all.)

Anyway, you'll want a card if you don't already have one and know that most shops always have a few lying around. Don't trust CMYK values unless you know where they came from and where they're going. And yes, certain paint and certain media / substrates are available.

The fact they specify exposure is to be keyed off the 18% is incorrect (unless one knows the correction factor here) is not your concern but might explain why they gave you a CMYK value to begin with. IMO, they might use some lessons from RIT to better know some of their science.

 

[Asuma01]

RIT? This? https://www.rit.edu/cos/colorscience/ac_ssc.php

 

[TimToad]

Oracal has this handy conversion chart that gets you close, but with every printer and profile creating slightly different results, we only consider these a starting point.

 

[ColorCrest]

RIT? This? https://www.rit.edu/cos/colorscience/ac_ssc.php

That should be the ticket!

 

[ColorCrest]

Oracal has this handy conversion chart that gets you close, but with every printer and profile creating slightly different results, we only consider these a starting point.

Seems Oracal could use the same course from RIT, unfortunately. Their recipes for RGB grey are telling among other things such as they don't include what RGB space they're using, etc.

 

[Signed Out]

I looked at your CMYK mix in Corel Draw and looked at a vinyl color chart to see which was closest. But just from experience I was guessing that was going to be the closest. However, I doubt that it will be a specific perfect match to 18% neutral gray if you have to meet those specs. Usually when photographers have to make 18% gray walls, etc., they paint the wall. There are standard formulas for making 18% gray paint, and there's even $80/qt paint that is premade to 18% gray.

Awesome, thanks for the info. We are making a test run to start. Think I'll do one with cut vinyl and one printed. Is it safe to say that these need to have a matte finish?

Edit: didn't see the additional responses after what I quoted here. Just ordered a gray card, never had a need for one before. So basically I'm just going to be trying to match my color to the card as best I can?

 

[Signed Out]

No, the CMYK will not be good there. You were correct to ask for a Pantone ID as that system is designed to communicate a color. However, because they are being so specific, they should have provided you with an actual Kodak gray card. Also, (me being facetious) anyone in upstate New York should be able to grab a Kodak gray card from their back pocket. (Kodak, RIT, and all.)

Anyway, you'll want a card if you don't already have one and know that most shops always have a few lying around. Don't trust CMYK values unless you know where they came from and where they're going. And yes, certain paint and certain media / substrates are available.

The fact they specify exposure is to be keyed off the 18% is incorrect (unless one knows the correction factor here) is not your concern but might explain why they gave you a CMYK value to begin with. IMO, they might use some lessons from RIT to better know some of their science.

So there are substrates available already this color? Dibond or ACM? I've been searching for it without luck. Does anybody have a link?

 

[unclebun]

Yes, it has to be matte finish