CMYK vs. RGB

wrote in message

I’m saving TIF files for printing in RGB mode (I’m currently using a consumer grade HP RGB printer) and they look great when I print.
If we want to upgrade down the line to use a professional grade printer (they all use CMYK as I understand it?). If I go in and change the TIF images to CMYK mode in Photoshop, am I going to lose anything with the quality of the image itself? or does the CMYK mode just have a bearing on the printer side of things and how it handles the printing of the image?

Thanks for any assistance.
Mike

Have you looked at any of the Professional Grade Printers?

Which ones use CMYK?

Roy G.

Roy G wrote:

wrote in message

I’m saving TIF files for printing in RGB mode (I’m currently using a consumer grade HP RGB printer) and they look great when I print.
If we want to upgrade down the line to use a professional grade printer (they all use CMYK as I understand it?). If I go in and change the TIF images to CMYK mode in Photoshop, am I going to lose anything with the quality of the image itself? or does the CMYK mode just have a bearing on the printer side of things and how it handles the printing of the image?
Mike

Have you looked at any of the Professional Grade Printers?
Which ones use CMYK?

Almost all printers use inks based on CMYK. That’s not important, though. What’s important is that most printers, even those ‘professional grade’ ones, have printer drivers that expect RGB imput.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl

In article ,
says…

I’m saving TIF files for printing in RGB mode (I’m currently using a consumer grade HP RGB printer) and they look great when I print.
If we want to upgrade down the line to use a professional grade printer (they all use CMYK as I understand it?). If I go in and change the TIF images to CMYK mode in Photoshop, am I going to lose anything with the quality of the image itself? or does the CMYK mode just have a bearing on the printer side of things and how it handles the printing of the image?

Thanks for any assistance.
Mike

If by "professional grade printers," you mean taking the image to an offset printing house, then you will only loose the difference in gamut between RGB & CMYK, which you can preview.

If you mean "professional grade printers," i.e. pro-desktop, then they will still want to see RGB and will convert for you.

With an offset printing house, make sure that you get THEIR CMYK specs, as there could well be differences. If you do this, just save the file, after the Mode change, with CMYK in the name. If you use different houses, with different specs. then set up a list of CMYK specs. and name them 01 – X and name accordingly.

Hunt

Johan W. Elzenga wrote:

Roy G wrote:

wrote in message

I’m saving TIF files for printing in RGB mode (I’m currently using a consumer grade HP RGB printer) and they look great when I print.
If we want to upgrade down the line to use a professional grade printer (they all use CMYK as I understand it?). If I go in and change the TIF images to CMYK mode in Photoshop, am I going to lose anything with the quality of the image itself? or does the CMYK mode just have a bearing on the printer side of things and how it handles the printing of the image?
Mike

Have you looked at any of the Professional Grade Printers?
Which ones use CMYK?

Almost all printers use inks based on CMYK. That’s not important, though. What’s important is that most printers, even those ‘professional grade’ ones, have printer drivers that expect RGB imput.

I think Roy means that he considers inkjet printers with 6/7/8 inks as professional, not the 4 ink versions.

Waldo

Waldo wrote:

Have you looked at any of the Professional Grade Printers?
Which ones use CMYK?

Almost all printers use inks based on CMYK. That’s not important, though. What’s important is that most printers, even those ‘professional grade’ ones, have printer drivers that expect RGB imput.

I think Roy means that he considers inkjet printers with 6/7/8 inks as professional, not the 4 ink versions.

Possibly, but that doesn’t change a thing. Those 6/7/8 inks printers are also based on CYMK colors. The extra inks are light versions of C, M and
K. However, if you use the standard printer drivers (not a RIP), you
still need to feed them RGB data.

And yes, there are even printers now which use a mix of CMYK inks and red and/or blue ink, but again their drivers still expect RGB input.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl

Possibly, but that doesn’t change a thing. Those 6/7/8 inks printers are also based on CYMK colors. The extra inks are light versions of C, M and
K. However, if you use the standard printer drivers (not a RIP), you
still need to feed them RGB data.

When CMYK is sended, internally it is separated to the 6/7/8 inks via an intermediate color space. With a 4 color process and 4 color data in the correct space, you can bypass it. Of course it also works with more colors, but I don’t know a lot of people editing images in 8 colors 😉

And yes, there are even printers now which use a mix of CMYK inks and red and/or blue ink, but again their drivers still expect RGB input.

True and I see nothing wrong in that way of working.

Instead of red+blue it is more common to have either a light cyan+magenta(+gray) or green+orange.

Waldo

Waldo wrote:

Possibly, but that doesn’t change a thing. Those 6/7/8 inks printers are also based on CYMK colors. The extra inks are light versions of C, M and
K. However, if you use the standard printer drivers (not a RIP), you
still need to feed them RGB data.

When CMYK is sended, internally it is separated to the 6/7/8 inks via an intermediate color space. With a 4 color process and 4 color data in the correct space, you can bypass it. Of course it also works with more colors, but I don’t know a lot of people editing images in 8 colors 😉

Unfortunately, that is not the way things happen in practise. Most printer drivers are not intelligent enough to do what you say when you send them CMYK data. What they do is convert the CMYK to RGB, and then process the RGB in the same way as if you’d sent RGB in the first place. The result is that sending CMYK data to such a printer almost always leads to poor results.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl

Johan W. Elzenga wrote:

Waldo wrote:

Possibly, but that doesn’t change a thing. Those 6/7/8 inks printers are also based on CYMK colors. The extra inks are light versions of C, M and
K. However, if you use the standard printer drivers (not a RIP), you
still need to feed them RGB data.

When CMYK is sended, internally it is separated to the 6/7/8 inks via an intermediate color space. With a 4 color process and 4 color data in the correct space, you can bypass it. Of course it also works with more colors, but I don’t know a lot of people editing images in 8 colors 😉

Unfortunately, that is not the way things happen in practise. Most printer drivers are not intelligent enough to do what you say when you send them CMYK data. What they do is convert the CMYK to RGB, and then process the RGB in the same way as if you’d sent RGB in the first place. The result is that sending CMYK data to such a printer almost always leads to poor results.

That’s true for non-PostScript printers, like consumer inkjets. The poor result you describe are from two poor color conversions needed for that. Printing via PostScript retains CMYK data depending on your specific settings (e.g. "Leave color unchanged").

Waldo

Waldo wrote:

Unfortunately, that is not the way things happen in practise. Most printer drivers are not intelligent enough to do what you say when you send them CMYK data. What they do is convert the CMYK to RGB, and then process the RGB in the same way as if you’d sent RGB in the first place. The result is that sending CMYK data to such a printer almost always leads to poor results.

That’s true for non-PostScript printers, like consumer inkjets. The poor result you describe are from two poor color conversions needed for that. Printing via PostScript retains CMYK data depending on your specific settings (e.g. "Leave color unchanged").

So tell me which inkjet printer uses postscript (using the standard drivers, not a RIP)… Even my Epson Stylus Pro 7600 does not.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl

Johan W. Elzenga wrote:

Waldo wrote:

Unfortunately, that is not the way things happen in practise. Most printer drivers are not intelligent enough to do what you say when you send them CMYK data. What they do is convert the CMYK to RGB, and then process the RGB in the same way as if you’d sent RGB in the first place. The result is that sending CMYK data to such a printer almost always leads to poor results.

That’s true for non-PostScript printers, like consumer inkjets. The poor result you describe are from two poor color conversions needed for that. Printing via PostScript retains CMYK data depending on your specific settings (e.g. "Leave color unchanged").

So tell me which inkjet printer uses postscript (using the standard drivers, not a RIP)… Even my Epson Stylus Pro 7600 does not.

Most of the Encads I know. When not using a RIP for your Epson, you are using it in the same manner as any other ("consumer") inkjet printer.

Waldo

"Waldo" wrote in message

Johan W. Elzenga wrote:

Roy G wrote:

wrote in message

I’m saving TIF files for printing in RGB mode (I’m currently using a consumer grade HP RGB printer) and they look great when I print.
If we want to upgrade down the line to use a professional grade printer (they all use CMYK as I understand it?). If I go in and change the TIF images to CMYK mode in Photoshop, am I going to lose anything with the quality of the image itself? or does the CMYK mode just have a bearing on the printer side of things and how it handles the printing of the image?
Mike

Have you looked at any of the Professional Grade Printers?
Which ones use CMYK?

Almost all printers use inks based on CMYK. That’s not important, though. What’s important is that most printers, even those ‘professional grade’ ones, have printer drivers that expect RGB imput.

I think Roy means that he considers inkjet printers with 6/7/8 inks as professional, not the 4 ink versions.

Waldo

Hi.

I just wanted to know which pro printers he had been looking at, because as far as I know almost all inkjets need RGB input.

I wanted to know which ones, he believed, required CMYK, so that I could put him right.

Roy G

Roy G wrote:

"Waldo" wrote in message

Johan W. Elzenga wrote:

Roy G wrote:

wrote in message

I’m saving TIF files for printing in RGB mode (I’m currently using a consumer grade HP RGB printer) and they look great when I print.
If we want to upgrade down the line to use a professional grade printer (they all use CMYK as I understand it?). If I go in and change the TIF images to CMYK mode in Photoshop, am I going to lose anything with the quality of the image itself? or does the CMYK mode just have a bearing on the printer side of things and how it handles the printing of the image?
Mike

Have you looked at any of the Professional Grade Printers?
Which ones use CMYK?

Almost all printers use inks based on CMYK. That’s not important, though. What’s important is that most printers, even those ‘professional grade’ ones, have printer drivers that expect RGB imput.

I think Roy means that he considers inkjet printers with 6/7/8 inks as professional, not the 4 ink versions.

Waldo

Hi.

I just wanted to know which pro printers he had been looking at, because as far as I know almost all inkjets need RGB input.

I wanted to know which ones, he believed, required CMYK, so that I could put him right.

Roy G

Sorry, the conversation got into a discussion less related to the original question.

For printing to digital printers you are right. I actually hardly ever do something in CMYK, I’ll let the RIP decide according to specific settings what is the best. When working in CMYK, you already chosen some color "artefacts" (at least that holds for most CMYK color spaces).

Waldo