Help with RGB color on a sign

[ProPrinting]

I have a customer who is wanting realty signs. The problem is their company color is in RGB and it doesnt convert to CMYK. They want the bright lime green, and its not that color when converted to CMYK. They want this to be printed on metal signs for their realty business.
Every sign printer I've talked to uses CMYK and cant replicate the lime color. Is there something I can do to make this work?

 

[Seeking Knowledge]

Hello,

At some point an RGB color has to be converted to CMYK if it is going to print. My suggestion would be is to leave it as RGB and let your RIP do the conversion. Do Not Convert in the adobe software as that is a dumb conversion, converting it a the RIP will give you the closest output providing you do a decent job of color management.

Now if it has to match 100% I would suggest screen printing it, looks like an easy two color job.

SK

 

[PricelineNegotiator]

Pretty easy fix. Just convert the printer to RGB instead of CMYK. Ask your sign printer to do this - if they don't know how just hang up and call the next sign shop.

 

[gordo]

I have a customer who is wanting realty signs. The problem is their company color is in RGB and it doesnt convert to CMYK. They want the bright lime green, and its not that color when converted to CMYK. They want this to be printed on metal signs for their realty business.
Every sign printer I've talked to uses CMYK and cant replicate the lime color. Is there something I can do to make this work?

Am I missing something? Looks like a two color sign - spot slime green and black. Why are you using CMYK?

 

[Macmann]

What Gordo said.

 

[ProPrinting]

Thanks for the replies. I should have been clear that we are a digital only shop (and a very small one at that), so I have no experience in sign printing. Thank you for the help!

 

[gordo]

Thanks for the replies. I should have been clear that we are a digital only shop (and a very small one at that), so I have no experience in sign printing. Thank you for the help!

You would need to use or have access to an inkjet printer that has extended process colors I.e. has a cmykog ink set (I believe Ricoh and others have that capability) or ask your ink vendor if they carry a lime green ink cartridge for your printer that you can use to replace one of your cmyk inks for the job.

 

[Correct Color]

Given the image you posted, if the question is if that exact color is in the gamut of any outdoor signage-type inkjet printer...

The answer is no.

However, you may be able to get close enough to satisfy the customer.

The right track is to not 'convert to CMYK' before printing, but to send the RGB file to the RIP, and let the RIP do the conversion to the printer profile -- which will be CMYK or some expanded colorspace including colors beyond CMYK. Unfortunately though, there's no expanded colorspace out there that's going to get you anywhere close to that green. These days for outdoor signage, all you've really got in expanded gamut choices are red and orange, which are not going to help.

And the old green enhancements -- such as the CMYKOG in the old Epson GS6000, weren't nearly that bright.

So you're probably going to be printing to a CMYK inkset, but profiled correctly, some can come pretty close. (Remember, rule number one is that there's no such thing as simply "RGB" or "CMYK.") I ran this image through several profiles I have on hand, just soft-proofing, and some of them came close enough that I'm pretty certain a client would be happy enough with the result for a yard sign.

Some, and those include the Adobe CMYK default, SWOP, yeah, they won't get it done.

Understand though that this all has to do with how well a printer is profiled and how much of its capability a given profile yields, so where you are your mileage may vary -- a lot -- but I can say that properly profiled on glossy stock, the machine that has the inkset that will come closest to hitting this color is the Seiko/Oki M64S. Its inkset just so happens to be strong out to blue/green.

You would need to use or have access to an inkjet printer that has extended process colors I.e. has a cmykog ink set (I believe Ricoh and others have that capability) or ask your ink vendor if they carry a lime green ink cartridge for your printer that you can use to replace one of your cmyk inks for the job.

Not really feasible in inkjet, Gordo. It's a different world. Inking up a unit and printing a specific color just aren't viable everyday options. "Spot colors" has something of a different meaning, and all colors come from the process mix. That's why every job is a CMYK job.

Pretty easy fix. Just convert the printer to RGB instead of CMYK.

I'm really curious how such a thing would be done.



Mike Adams
Correct Color

 

[gordo]

[snip]

Not really feasible in inkjet, Gordo. It's a different world. Inking up a unit and printing a specific color just aren't viable everyday options. "Spot colors" has something of a different meaning, and all colors come from the process mix. That's why every job is a CMYK job.

I'm really curious how such a thing would be done.
Mike Adams
Correct Color

I suggested it because I seem to remember at least one brand of inkset printer (e.g. Roland Hi-Fi JET FH-740) that had orange and green as extra colors besides CMYK to expand the gamut.

 

[I.T. Supplies]

If you have an aqueous printer, you would most likely need a commercial edition model (like Epson P7000/P9000) with a Spectro and a color specialist to work on matching the colors properly. It's a few hour process, but it would most likely get you the color. Otherwise, it would be something via Solvent or Dye-Sub with a color specialist adjusting things to get the colors to match.

 

[gregbatch]

Job it out to a screen printer. https://thewholesalesignguy.com/screen-printed-aluminum-yard-signs/ They do wholesale trade work.

 

[Correct Color]

IT Supplies,

If you have an aqueous printer, you would most likely need a commercial edition model (like Epson P7000/P9000) with a Spectro and a color specialist to work on matching the colors properly. It's a few hour process, but it would most likely get you the color. Otherwise, it would be something via Solvent or Dye-Sub with a color specialist adjusting things to get the colors to match.

As a guy who makes a living as a "color specialist" I do have to point out that this is not the way it works.

A color is either in the gamut of a specific machine/media/ink/resolution combination, or it is not. The first key is to make a profile that captures every bit of the gamut available for that machine/media/ink/resolution combination, but the doing of that is in no way determined by any specific colors you want to print with that profile after it is created.

Once that profile is created, to print a spot color -- the digital description of 'spot color' in this case -- you just have to determine the L*a*b* value of that color and properly communicate it to the RIP. Of course there is a procedure for that, but it does not involve any sort of color matching. If all is done correctly and the color is in gamut, you'll get a match.

If it isn't, you'll get a close as the RIP can get, and no amount of supposed color voodoo will get you any closer.



Mike

 

[Sherbert]

I'm really curious how such a thing would be done.

Glad it's not just me!

 

[Danny Whitehead]

It's going to have to be screen printed, or they're going to have to change their corporate colour significantly. They're going to do the latter sooner or later anyway. It's just unfortunate that you're going to be the first to inform them of their mistake (unless they've already been told and are shopping around for someone who tells them what they want to hear).

 

[DYP]

The best that you can do to maximize the gamut of your printer to hit that color as close as possible is to assign specific output values for that color. You do that as a specific spot color with assigned output values or if your RIP has a replace color option you can do it there. To determine the best output value your RIP should have ability to print a chart of various values that will let you determine which output values will come the closest.

 

[old guy]

Pretty easy fix. Just convert the printer to RGB instead of CMYK. Ask your sign printer to do this - if they don't know how just hang up and call the next sign shop.

this is still funny