Roger,

Next step is the experimentation -- you'd imagine.

So I installed the profile in my Windows 10 PC and turned to Photoshop, naturally ;-) There must zillions of "advanced" proprietary packages that offer all kinds of "advanced" tools for those who thrive on multi-color profiles?

Not really. Fact is that multi-color was always a pretty small niche of the industry, and nowadays many multi-color machine manufacturers as well as RIP manufacturers have “contoned” the process, meaning that it’s done internally, and what you generate is simply a CMYK profile, so, sadly, you could call multi-color profiling something of a dying art.

So, I took a grayscale image and converted it to the muti-color profile.

After conversion, I end up with three extra channels, Red, Green and Blue. Fair.

Two things.

First, read the CIE Lab values returned good neutrals (a* and b* = 0). Second, the appearance of the image didn't evoke anything neutral but more like "red" cast?

This may be more a question for the Photoshop Forum on Adobe's web site but, in case..., is the user expect to "Edit" the RGB Channels after conversion? To obtain a correct color appearance?

It would seem that way…

No. Fact is Photoshop has never rendered an accurate screen image of any multi-color profile once you go ahead and make the conversion. You may also have noted that if you install a multi-color profile and go look for it to soft-proof with, it won’t be there. However, you can get a pretty good idea of how a multi-color profile will look printed by going to convert to profile, selecting the mc profile you want, and clicking “preview.” You’ll probably have to drag the box out of the way, but what’s on the screen then is a pretty good representation. Then of course if you go ahead and click OK, it whacks out. A couple things though: First is that any multi-color profile — is made for a very specific printing condition. I can’t image really why you’d ever want to do a conversion in Photoshop to begin with. If you don’t have the entire printing condition at hand — machine/media/resolution/ink/density/RIP — then your converted result is going to be pretty useless to you. And if you do, well, then use the RIP to do the conversion. That’s what it’s for. Second is that properly made and properly used, the value of N-colors is to extend gamut beyond CMYK. Differing profiling packages have differing controls, and I guess it’s at least possible for someone making a multi-color profile to extend the N-channels into non-chroma areas. But there’s no reason to. So if you’re doing any tests starting with a greyscale image, once you get the other channels — whatever they are — they should all be empty. Mike Adams Correct Color

Max, As Roger's OP was in reference to a printing press I assume he was referring to so-called 'hi-fi' printing on an offset litho printing press. I would have thought that G Mike Adams was right in observing that it was a dying art as the demand for this type of printing was never mainstream and the benefits were only apparent when the copy contained a lot of highly saturated colours. In other words, it was a niche market with marginal differentiation to conventional 4-col offset printing with significantly higher setup costs. In times that are tough for connectional 4-col offset printing I would be surprised that there is much interest outside of 'academic' circles. Add to these challenges that of getting designers to embrace the concept and the 'bugs' inherent in applications like Photoshop that limited the ability to preview the end result and it ends up as a technology looking for a purpose. In the end, the cost did not justify the means. As offset printing in general continues to decline I would have thought that hi-fi writing was bordering on the 'endangered species' list. I am wondering if the distinction between multi-colour 'hi-fi' offset litho printing and multi-colour inkjet printing where devices commonly (?) use several 'shades' of C, M, Y and K as well as Red, Orange and Green is being addressed. I thought sending RGB files to these devices and letting the RIP handle the conversion was standard practice and the use of profiles for achieving predictable results had settled on a range of standards-based colour gamuts that reflected commonly used sets of 4-col offset printing conditions as their target(s). What use are multi-colour profiles outside of the RIP in this scenario? Mark Stegman Graphic Technologist On 23 December 2015 at 07:31, Max Derhak <Max.Derhak@onyxgfx.com> wrote:

I wouldn't say that multi-color profiling is something of a dying art.

I'd classify it as a fairly tricky thing to do with some serious caveats WRT V4 ICC profiles. Some of the challenges include: 1. Dimensional complexity makes characterization challenging. You need lots more patches to get good characterization. What works for 4 colors becomes overwhelming for 7 colors. 2. Ink Load issues (lots more ink possibilities 3. Dimensional complexity makes device to PCS A2Bx tags in profiles really really big or rather inaccurate. The size of the n-dimensiona tables is determined by the number of sampling points raised to the power of the number of device channels. Its an exponential problem often resulting in much sparser sampling of the device address space to keep the profile size reasonable. 4. Ink separation is much more involved to get good smooth transitions while achieving full gamut available with extra inks. In the B2Ax PCS to device tables there is only 1 way to specify how to achieve each Lab value. 5. Large differences in ink values for adjoining grid points in the B2Ax output table separation can result in greater interpolation errors between grid points.

Thus when you use a multi-color icc profile in Photoshop it is very likely the preview will be less than desirable, and most likely not a faithful representation of the actual output.

With up and coming iccMAX based multi-color profiles there are greater possibilities to either directly model mathematically the characterization of the inkset or use selection of lower dimensional sub tables for greater accuracy profiles of smaller size.

Max Derhak (PhD) Principal Scientist Onyx Graphics Co-Chair International Color Consortion

-----Original Message----- From: colorsync-users-bounces+max.derhak=onyxgfx.com@lists.apple.com [mailto:colorsync-users-bounces+max.derhak=onyxgfx.com@lists.apple.com] On Behalf Of G Mike Adams Sent: Tuesday, December 22, 2015 11:10 AM To: Roger Breton Cc: 'colorsync-users?lists. apple. com' List Subject: Re: Multi-color ICC profiles

Roger,

...

Next step is the experimentation -- you'd imagine.

So I installed the profile in my Windows 10 PC and turned to Photoshop, naturally ;-) There must zillions of "advanced" proprietary packages that offer all kinds of "advanced" tools for those who thrive on multi-color profiles?

Not really. Fact is that multi-color was always a pretty small niche of the industry, and nowadays many multi-color machine manufacturers as well as RIP manufacturers have “contoned” the process, meaning that it’s done internally, and what you generate is simply a CMYK profile, so, sadly, you could call multi-color profiling something of a dying art.

...

So, I took a grayscale image and converted it to the muti-color profile.

After conversion, I end up with three extra channels, Red, Green and

Blue. Fair.

...

Two things.

First, read the CIE Lab values returned good neutrals (a* and b* = 0). Second, the appearance of the image didn't evoke anything neutral but

more like "red" cast?

...

This may be more a question for the Photoshop Forum on Adobe's web site

but, in case..., is the user expect to "Edit" the RGB Channels after conversion? To obtain a correct color appearance?

...

It would seem that way…

No.

Fact is Photoshop has never rendered an accurate screen image of any multi-color profile once you go ahead and make the conversion. You may also have noted that if you install a multi-color profile and go look for it to soft-proof with, it won’t be there.

However, you can get a pretty good idea of how a multi-color profile will look printed by going to convert to profile, selecting the mc profile you want, and clicking “preview.” You’ll probably have to drag the box out of the way, but what’s on the screen then is a pretty good representation. Then of course if you go ahead and click OK, it whacks out.

A couple things though:

First is that any multi-color profile — is made for a very specific printing condition. I can’t image really why you’d ever want to do a conversion in Photoshop to begin with. If you don’t have the entire printing condition at hand — machine/media/resolution/ink/density/RIP — then your converted result is going to be pretty useless to you.

And if you do, well, then use the RIP to do the conversion. That’s what it’s for.

Second is that properly made and properly used, the value of N-colors is to extend gamut beyond CMYK. Differing profiling packages have differing controls, and I guess it’s at least possible for someone making a multi-color profile to extend the N-channels into non-chroma areas. But there’s no reason to. So if you’re doing any tests starting with a greyscale image, once you get the other channels — whatever they are — they should all be empty.

Mike Adams Correct Color _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription:

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My observations are more related to the fact that I really haven’t seen multi-color printing as a big thing overall up to this point, so it’s hard to say that it’s an ebbing or a dying art. Additionally, within recent ICC meetings the push to go HIFI seems to be picking up in the packaging industry since it has the possibility of reducing costs to get spot colors without having to constantly change ink sets. (I may be wrong in this but this has been my general observation). However, standardizing things to match operations and procedures used in conventional CMYK printing appears to still be in its infancy – if it will fly at all. I firmly believe that iccMAX may offer potential to address some issues that cannot be addressed with legacy ICC approaches. Also, multi-color becomes important when you start printing onto fabrics or ceramics were the gamuts are restricted by the inherent limitations of the medium involved. In other areas of large format printing I also agree that it is much easier to let the printer manufacturer do the multi-ink separation and then just send RGB to the device. However, as was stated by Mike you are then limited to the constraints of what the manufacturer allows or enables in terms of media and ink use. Having full control of multi-color ink use has both its benefits and challenges. I readily admit that it is often challenging to get right in all circumstances, and using multi-color separations outside of the RIP does become rather unwieldy. It’s something that we at Onyx Graphics have endeavored to work on and improve for several years now with no thought that it is going to stop anytime soon. That is part of the reason that we have invested considerably into pushing for standardization of color management systems enabled by iccMAX that have capabilities that go way beyond what you are capable of achieving with V2/V4 ICC profiles. However, for conventional CMYK printing such a system really isn’t needed, and if that is your focus then it might be easy to see multi-color as a passing fad. Max Derhak (PhD) Principal Scientist From: G Mike Adams [mailto:typhoon@correctcolor.org] Sent: Wednesday, December 23, 2015 10:33 AM To: Mark Stegman Cc: Max Derhak; 'colorsync-users?lists. apple. com' List Subject: Re: Multi-color ICC profiles Mark, As Roger's OP was in reference to a printing press I assume he was referring to so-called 'hi-fi' printing on an offset litho printing press. I’m not so sure of that. He really didn’t say. And since profiles beyond CMYK are more prevalent in large format printing than any other segment of the industry, that’s what I assumed when I read the initial post. I thought sending RGB files to these devices and letting the RIP handle the conversion was standard practice and the use of profiles for achieving predictable results had settled on a range of standards-based colour gamuts that reflected commonly used sets of 4-col offset printing conditions as their target(s). What use are multi-colour profiles outside of the RIP in this scenario? That’s not exactly the scenario. What a RIP does is convert pixel information, pixel by pixel, into dot information. So what a profile does is define to the RIP how the printer prints. The point of the profile isn’t to achieve some standard; it’s to recreate the actual color of each pixel in the incoming color space in the destination (printer profile) color space. Or, if a pixel’s color is out of the gamut of the destination space, to render as close a representation as possible. These days, the main reason for beyond-CMYK inksets in general — and in large format in particular — is to be able — basically — to hit more Pantone colors. Not the only reason; there are still fine-art aqueous printers that use multi-channel mainly for photographic gamut, but the action the past several years has been in matching spot colors. Best example is 021 Orange, or Home Depot Orange. You can’t get there with CMYK. Any CMYK. Add orange to the inkset, and you can. But when you do, you then have to profile to determine just how this inkset is printing. And you want to create dots accordingly. If the point of your profile was to align your printer with SWOP, or Gracol, or whatever, you’d be right back where you started, and you might as well not even have the orange. But I do agree, except for soft proofing — which is possible but problematic in Photoshop — these profiles have basically no use outside of the RIP. Mark, I wouldn't say that multi-color profiling is something of a dying art. Well don’t get me wrong. I love doing beyond-CMYK profiles. In fact, I love doing beyond-CMYK profiles with SepCntrl in Onyx on Canon iPFx400 printers — just about as intricate a profiling procedure as there is. As a profiler, I like to be able to take full control of every facet of how the printer prints in order to make the best possible use of all its capabilities in every environment on every media. But how many people do that? How many people profiling that machine do 7 color profiles, and how many just do RGB contone? Also, maybe you’re not aware, but in your competitor Caldera, it’s not possible to make a more-than-CMYK profile. Regardless of the inkset, you create a CMYK profile, and the RIP does the conversion to the final actual colors. Not sure if the term is entirely right, but I think of that as ‘contoning’ the process… and I hate it. Hate it so much that I argued with one guy at Caldera about it until I was nearly blue in the face. He seemed so completely obtuse about the entire issue that eventually I gave up. Also of note is that in Onyx, while it is possible to use SepCntrl and create CMYKO profiles for the Epson SureColor, when you install them, they don’t work. The only way to profile these machines in Onyx is to let RIP ‘contone’ the orange split. And I hate that just as much as I do in Caldera. I’ve reported this twice as a bug, btw. Gotten nowhere. If you’re interested, feel free to contact me off list. The above are all reasons it appears to me that multi-channel profiling is a dying art. I'd classify it as a fairly tricky thing to do with some serious caveats WRT V4 ICC profiles. Some of the challenges include: 1. Dimensional complexity makes characterization challenging. You need lots more patches to get good characterization. What works for 4 colors becomes overwhelming for 7 colors. Interestingly, while that’s no doubt theoretically true, my experience in the real word is that I get the best — by far — multi-channel profiles out of Monaco. Amazingly small patch sets — particularly at 5 color — and I had hoped for better things out of i1P -- basically the Monaco engine and more patches. But I’ve seen i1P fall down. Monaco never does. Mike Adams Correct Color

Roger, Interesting…

Perhaps I need to add a bit of context to my original post...

You see, I may land a job with a printer who routinely prints packaging on an 8 color Roland offset press.

As you may know, packaging is typically printed on, say, 20pts recycled board or SBS, using 50" and 56" wide 6 colors presses, with mostly CMYK and two spot inks.

This particular printer claim they try to avoid printing with 6 colors to print instead with 7 colors, CMYK + RGB, for economic reasons.

My first thought would be that that’s extremely odd. From my experience — which is exclusively in large-format inkjet but still I think applicable — what I have seen is that there is absolutely zero advantage in an actual CMYKRGB inkset. The reason being that RG & B can always be made from CMYK. There’s no gamut gain to adding them. In fact, from the few times I’ve seen inksets that actually were trying to use RG or B, what I’ve seen is the profile-making engine get confused as to which is the true primary to map to, the combination primary or the solid ink primary. The results I’ve seen have been pretty much useless. That’s why every “CMYKRGB” inkset that I’ve seen in large format is in actuality CMYKOGV. I’ve always figured the “CMYKRGB" stuff was just marketing. “Hey, these guys always talk about CMYK and RGB. Let’s just call this CMYKRGB, and it’ll look like we’re using them all!” I’d be curious just what primaries these guys are actually using.

They say they developed a custom multi-color profile which they supply to clients who want to directly convert their artwork to their press in Photoshop.

Wow. All I can say is that I would not advise anyone to do that. Any time. Ever. If they want to send out a profile for soft-proofing, fine. But the only way a client can do that is the way I showed you previously. I wouldn’t take that chance. More importantly though, I’ve had some talks with some potential clients who have been attempting something similar, and every single one of them has been looking into such a system as a way to run one setup and hit the entire Pantone Library. And if that’s the goal, Photoshop doesn’t really come into the equation. Most every designer who makes artwork for such a process is going to create it in Illustrator, send the art as a .pdf, leave the spot colors defined as spots, and the goal of the profiles and the RIP is to make them match their solid PMS equivalents. Honestly, it sounds to me like these guys are barreling full-throttle ahead down a dead-end street.

What's interesting, to me, is that, from a production efficiency standpoint, by converting most jobs to this 7 color printing scheme, they effectively avoid wash-ups, reduce custom inks inventory and considerably reduce make-readies since they minimize the number of printing sequence change and can get a better utilization of press time overall.

It’s theoretically possible. Lots of people have looked into it. Whether anyone is actually there, maybe someone else on the list who plays more in that arena would know. Mike

My question is, can I use multi color .icc profiles with my workflow….and how? Printer is the Epson Pro 9900, printer software is LSI’s Printao 8. And I also print with LR 6.3 stand alone. I profiles with i1 Profiler and i1Pro version D. 1155 patches for paper profiling. David Millers’ Photography L.L.C. David B. Miller, Pharm. D., member dba Spinnaker Photo imaging Center 3809 Alabama Street Bellingham, WA 98226-4585 360 739 2826 david@spinnakerphotoimagingcenter.com <mailto:david@spinnakerphotoimagingcenter.com>

On Dec 23, 2015, at 7:32 AM, G Mike Adams <typhoon@correctcolor.org> wrote:

Mark,

...

As Roger's OP was in reference to a printing press I assume he was referring to so-called 'hi-fi' printing on an offset litho printing press.

I’m not so sure of that. He really didn’t say. And since profiles beyond CMYK are more prevalent in large format printing than any other segment of the industry, that’s what I assumed when I read the initial post.

...

I thought sending RGB files to these devices and letting the RIP handle the conversion was standard practice and the use of profiles for achieving predictable results had settled on a range of standards-based colour gamuts that reflected commonly used sets of 4-col offset printing conditions as their target(s). What use are multi-colour profiles outside of the RIP in this scenario?

That’s not exactly the scenario.

What a RIP does is convert pixel information, pixel by pixel, into dot information. So what a profile does is define to the RIP how the printer prints. The point of the profile isn’t to achieve some standard; it’s to recreate the actual color of each pixel in the incoming color space in the destination (printer profile) color space. Or, if a pixel’s color is out of the gamut of the destination space, to render as close a representation as possible.

These days, the main reason for beyond-CMYK inksets in general — and in large format in particular — is to be able — basically — to hit more Pantone colors. Not the only reason; there are still fine-art aqueous printers that use multi-channel mainly for photographic gamut, but the action the past several years has been in matching spot colors.

Best example is 021 Orange, or Home Depot Orange. You can’t get there with CMYK. Any CMYK. Add orange to the inkset, and you can. But when you do, you then have to profile to determine just how this inkset is printing. And you want to create dots accordingly. If the point of your profile was to align your printer with SWOP, or Gracol, or whatever, you’d be right back where you started, and you might as well not even have the orange.

But I do agree, except for soft proofing — which is possible but problematic in Photoshop — these profiles have basically no use outside of the RIP.

Mark,

...

...

I wouldn't say that multi-color profiling is something of a dying art.

Well don’t get me wrong. I love doing beyond-CMYK profiles. In fact, I love doing beyond-CMYK profiles with SepCntrl in Onyx on Canon iPFx400 printers — just about as intricate a profiling procedure as there is. As a profiler, I like to be able to take full control of every facet of how the printer prints in order to make the best possible use of all its capabilities in every environment on every media.

But how many people do that?

How many people profiling that machine do 7 color profiles, and how many just do RGB contone?

Also, maybe you’re not aware, but in your competitor Caldera, it’s not possible to make a more-than-CMYK profile. Regardless of the inkset, you create a CMYK profile, and the RIP does the conversion to the final actual colors. Not sure if the term is entirely right, but I think of that as ‘contoning’ the process…

and I hate it. Hate it so much that I argued with one guy at Caldera about it until I was nearly blue in the face. He seemed so completely obtuse about the entire issue that eventually I gave up.

Also of note is that in Onyx, while it is possible to use SepCntrl and create CMYKO profiles for the Epson SureColor, when you install them, they don’t work. The only way to profile these machines in Onyx is to let RIP ‘contone’ the orange split.

And I hate that just as much as I do in Caldera.

I’ve reported this twice as a bug, btw. Gotten nowhere. If you’re interested, feel free to contact me off list.

The above are all reasons it appears to me that multi-channel profiling is a dying art.

...

...

I'd classify it as a fairly tricky thing to do with some serious caveats WRT V4 ICC profiles. Some of the challenges include: 1. Dimensional complexity makes characterization challenging. You need lots more patches to get good characterization. What works for 4 colors becomes overwhelming for 7 colors.

Interestingly, while that’s no doubt theoretically true, my experience in the real word is that I get the best — by far — multi-channel profiles out of Monaco.

Amazingly small patch sets — particularly at 5 color — and I had hoped for better things out of i1P -- basically the Monaco engine and more patches.

But I’ve seen i1P fall down.

Monaco never does.

Mike Adams Correct Color

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