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Reds print worst on my Canon ipf6400


Beat C
 

I have just reread Chapter 12 (Managing Color Settings) of Dan’s Professional Photoshop book (5th Edition).

Although I never print on a commercial CMYK printing press, I found the text about CMYK highly illuminating. I think it’s necessary to understand CMYK, alongside the possibilities that CMYK offers in the editing process.

I always print on my Canon ipf 6400 inkjet printer. The printer uses besides the customary C, M, Y and K inks, 8 additional inks : Red, Green, Blue, Light Cyan, Light Magenta, Light Grey, Mid Grey and an additional matte Black. Twelve inks in total.

Blue is the most difficult color in CMYK printing. But as Dan writes on page 286, if additional inks are used, all bets are off. My experience is that Red reproduces worst. Bright Red is always, on all papers, quite flat and washed out in comparison to the other colours.

I would like to make my prints better (they are not bad, but could be better, I am sure). So my question comes down to two things I guess :

1. I send a rgb file (in my case Adobe RGB) through a paper profile and correct Media Settings to my printer. The hard- and software of the printer will translate the rgb file into the amount and place of the 12 inks in the correct amounts on the paper. Unfortunately I have no say in this in the current situation.

If the colours are not exactly the same as on the screen, I could use a curve (color mode).
If the contrast, or darkness is different, a curve might also help.

But loss of detail due to too much ink is something I would not be able to correct myself in PS. As I use the Mirage Print plugIn (the Canon print plugIn is horrible, just as horrible as the software of the printer), I seem to be able to change some settings in the profiles, but only on a general (profile basis) and not from image to image basis. Also it is a bit unclear as to what I am actually changing in the settings in Mirage.

Are there possibilities to tweak the translation? So fiddling with the Canon translation from rgb to 12 inks? Would it be of any use if possible? Would RIP software do anything besides relieving me of my money?

Has Dan written things about how the files go from rgb (in PS) to a multi-ink inkjet printer? It would be great to have an as detailed understanding of the practical and theoretical aspects of printing on a multi-ink inkjet printer as is explained for CMYK in Dan’s books.

On a much narrower field : how do I get better reds? As the printer has a red ink cartridge, I don’t get it that the reds are so weak.
Actually, the Blues are quite satisfying.

2. My prints are most of the times a little too dark, although I have my monitor set to 80 candela’s. I don’t think I can get any lower. I can compensate with a curve, but I like to understand why this is needed.

Beat


Rex Waygood
 

Your working space is smaller than the gamut of your printer in Reds, Blues, Cyan, Magenta. I only have access to Permajet Paper profiles and have tried a couple for your printer vs Adobe RGB. 
You could try processing a troublesome image in ProPhoto and make a comparison.  


Rex Waygood
 

I have created a video to show you.
Each square is ∆Eab = 10

On point 2, do you view your prints in a lightbox? 


john c.
 

I use the same inks in my ipf9400 and the reds are shocking, so it's not the printer. Are you sure you're using the correct printer media profile?

-----Original Message-----
From: Beat Cornaz b.cornaz@gmx.net [COLORTHEORY]
Sent: Tuesday, August 20, 2019 3:57 PM
To: COLORTHEORY@yahoogroups.com
Subject: [COLORTHEORY] Reds print worst on my Canon ipf6400

I have just reread Chapter 12 (Managing Color Settings) of Dan’s Professional Photoshop book (5th Edition).

Although I never print on a commercial CMYK printing press, I found the text about CMYK highly illuminating. I think it’s necessary to understand CMYK, alongside the possibilities that CMYK offers in the editing process.

I always print on my Canon ipf 6400 inkjet printer. The printer uses besides the customary C, M, Y and K inks, 8 additional inks : Red, Green, Blue, Light Cyan, Light Magenta, Light Grey, Mid Grey and an additional matte Black. Twelve inks in total.

Blue is the most difficult color in CMYK printing. But as Dan writes on page 286, if additional inks are used, all bets are off. My experience is that Red reproduces worst. Bright Red is always, on all papers, quite flat and washed out in comparison to the other colours.

I would like to make my prints better (they are not bad, but could be better, I am sure). So my question comes down to two things I guess :

1. I send a rgb file (in my case Adobe RGB) through a paper profile and correct Media Settings to my printer. The hard- and software of the printer will translate the rgb file into the amount and place of the 12 inks in the correct amounts on the paper. Unfortunately I have no say in this in the current situation.

If the colours are not exactly the same as on the screen, I could use a curve (color mode).
If the contrast, or darkness is different, a curve might also help.

But loss of detail due to too much ink is something I would not be able to correct myself in PS. As I use the Mirage Print plugIn (the Canon print plugIn is horrible, just as horrible as the software of the printer), I seem to be able to change some settings in the profiles, but only on a general (profile basis) and not from image to image basis. Also it is a bit unclear as to what I am actually changing in the settings in Mirage.

Are there possibilities to tweak the translation? So fiddling with the Canon translation from rgb to 12 inks? Would it be of any use if possible? Would RIP software do anything besides relieving me of my money?

Has Dan written things about how the files go from rgb (in PS) to a multi-ink inkjet printer? It would be great to have an as detailed understanding of the practical and theoretical aspects of printing on a multi-ink inkjet printer as is explained for CMYK in Dan’s books.

On a much narrower field : how do I get better reds? As the printer has a red ink cartridge, I don’t get it that the reds are so weak.
Actually, the Blues are quite satisfying.

2. My prints are most of the times a little too dark, although I have my monitor set to 80 candela’s. I don’t think I can get any lower. I can compensate with a curve, but I like to understand why this is needed.

Beat

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Posted by: Beat Cornaz <b.cornaz@gmx.net>
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Beat C
 

I have looked at the video Rex provided. I might be wrong, but I read the accompanying text :

Where the wire frame shows the AdobeRGB colourspace does not represent the colours that can be achieved in a Canon ipf6400 in this case using PermaJet FB Distinction.

as follows : The wireframe represents the Adobe RGB gamut and the Coloured frame is the paper profile.
But if I do the same in ColorSync, it is actually the other way around. I have also compared with the PermaJet FB Distinction profile. Incidentally, this profile is about the same as the Candon Lustre profile I often use. In both cases (as well with half a dozen other paper profiles I compared with Adobe RGB), the top (light) corner of the reds is bigger in as well sRGB (a little) as in Adobe RGB. It’s only if we go down (darker), the paper has a bigger gamut. So to be more specific, my problem lies in the bright saturated reds.
I surely use the correct paper profiles and the correct media settings. With Canson paper, it’s well organised on their website and the profiles and media Settings are all downloadable and easy to install.
This does not go for many other papers. My experience with MOAB are just terrible. I have a sample pack of MOAB papers, but cannot get the Media settings, also not after contacting the customer service thrice. Quite disappointing.
I use some other papers as well, but they all produce the same reds that turn out too dark and too unsaturated.

2. I have a daylight lamp, but I always check the prints in broad daylight and there they turn out a bit too dark.

Thanks, Beat


Rex Waygood
 

The big solid shape is the AdobeRGB colourspace. The wire frame is your printer profile. The Adobe RGB colour space does not represent colours that your printer can print in the Reds, Blues, Cyans and Magentas. Adobe RGB is recommended by Adobe for CMYK printing. Adobe recommend ProPhoto or other wide gamut colourspaces for Inkjet printers and other wide gamut outputs. Go to colour Settings select ProPhoto and Mouse over will reveal Adobe's advice for that profile at the bottom.
Sorry if I didn't make it clear.
The program I use is Color Think Pro.


Dan Margulis
 

Beat writes,

as follows : The wireframe represents the Adobe RGB gamut and the Coloured frame is the paper profile.
But if I do the same in ColorSync, it is actually the other way around. I have also compared with the PermaJet FB Distinction profile. Incidentally, this profile is about the same as the Candon Lustre profile I often use. In both cases (as well with half a dozen other paper profiles I compared with Adobe RGB), the top (light) corner of the reds is bigger in as well sRGB (a little) as in Adobe RGB. It’s only if we go down (darker), the paper has a bigger gamut. So to be more specific, my problem lies in the bright saturated reds. 
I surely use the correct paper profiles and the correct media settings. With Canson paper, it’s well organised on their website and the profiles and media Settings are all downloadable and easy to install. 
This does not go for many other papers. My experience with MOAB are just terrible. I have a sample pack of MOAB papers, but cannot get the Media settings, also not after contacting the customer service thrice. Quite disappointing.  
I use some other papers as well, but they all produce the same reds that turn out too dark and too unsaturated.

Despite all the palaver from the vendors and color management groupies about what a huge gamut these multi-ink devices have the truth is that in practice they rarely can produce a red that’s out of the sRGB space let alone something wider-gamut. Cyans, magentas, certain greens, and yellows, yes, but we rarely need the first three and can’t perceive the difference in the fourth. Blues, yes, because of the impact of a true blue ink when the currently available cyan inks aren’t very pure.

Red does not have these advantages. The theory is that magenta ink prevents reflection of green light, and the theory is correct: magenta ink is quite efficient as compared to cyan. Yellow ink is even better, it almost totally prevents reflection of blue. Mix the two together, and they eliminate green plus blue, allowing only red light to reflect off the print. That there is also a red ink available may or may not help. If it’s a different hue than the “red” the user wants it could actually be harmful.

The problem with this theory is that it doesn’t fully work unless the inks are absolutely, totally, utterly, completely, and perfectly transparent, such that the ability of yellow to absorb blue is unaffected by the fact it is covered with magenta ink. The inks are in fact very transparent but they don’t reach the level of perfection that the theoretical model requires.

Consequently the best we can do is to learn what *is* possible with the given printer. Sending over files with a strong red designated in ProPhoto as suggested previously, and then in LAB if available, is a good start. You need to know not just how strong a red is possible, but how strongly you have to contour it so that it shows detail instead of being just a colorful blob.

Dan Margulis


Beat C
 

>> Rex wrote :
>> The big solid shape is the AdobeRGB colourspace. The wire frame is your printer profile. The Adobe RGB colour space does not represent colours that your printer can print in the Reds, Blues, Cyans and 
>> Magentas. Adobe RGB is recommended by Adobe for CMYK printing.

Thanks Rex. I had read the explanation on the video the other way around. So the comparison shows what I encountered : 255,0,0 in Adobe RGB cannot be printed on paper. Going to an even bigger colorspace, like proPhoto or Wide Gamut will make the problem worse, as the 255,0,0 interpretation of the very big colorspaces make it even more ‘red’ and more unprintable.
What amazes me, is that the canon with it’s separate red ink cartridge can’t print it. Is it the ink or is it the paper?


>> Dan Margulis writes :
>> Red does not have these advantages. The theory is that magenta ink prevents reflection of green light, and the theory is correct: magenta ink is quite efficient as compared to cyan. Yellow ink is even better, 
>> it almost totally prevents reflection of blue. Mix the two together, and they eliminate green plus blue, allowing only red light to reflect off the print. That there is also a red ink available may or may not help. 
>> If it’s a different hue than the “red” the user wants it could actually be harmful.

Dan, can you explain the last sentence some more?

In my Canon printer I guess that the Red id the RGB red (as are the Green and the Blue inks). So sending a square of 255,0,0 to the printer should deliver the right bright red. Alas, it doesn’t and it’s way off. Dull and dark on different papers with different profiles. Of course. I’ll resign if it just is not possible to get a bright red, but I’d like to understand why it fails. Red is an important colour and Canon would be stupid if it put in Red ink, that doesn’t deliver.

>> Sending over files with a strong red designated in ProPhoto as suggested previously, and then in LAB if available, is a good start. 
>> You need to know not just how strong a red is possible, but how strongly you have to contour it so that it shows detail instead of being just a colorful blob.

Exactly. That is the reason I switched to Adobe RGB after having studied Dan’s books. I surely do not only want RED, but also details. Unfortunately, as already mentioned, even a solid blob of red is not achievable in my setUp.

Dan, have you somewhere written about how to optimal  use and prepare for multi ink printers? Your detailed explanations of how to prepare for a CMYK press was very inspiring and useful for me. Is there something in that vein for modern inkjets?


I just went to PS and made a document with squares of Red 255,0,0   Green 0,255,0    Blue 0,0,255. When starting with my normal Adobe RGB colorspace, all three are out of gamut on Canson Baryt paper.
The red gets an orange, the green a yellow green and the blue duller mostly darker, like the others as well. When assigning sRGB to the file, the colours get a bit duller and the Red is in gamut (G and B still out of gamut). When assigning ProPhoto, all get brighter and even more brilliant, and so even more out of gamut. 
So my conclusion is, that the greens and blues perform as good or as bad as the reds. I might have noticed it most with the reds.

>> Rex wrote :
>> Adobe recommend ProPhoto or other wide gamut colourspaces for Inkjet printers and other wide gamut outputs.

Dan refers to this as well. But I don’t get it. Going to a wider gamut only makes a more unprintable red as it gets even more out of gamut. The control over the rendering (bringing back the reds into gamut of the paper/ink) and control over details is even more lost. It would make more sense to me to reduce the colorspace, or apply curves, so the reds are tamed to be in the gamut of the paper/ink combination.

Does it make sense, to bring everything myself into gamut before printing? This in stead of letting the software decide where to shave corners. 


Thanks, Beat


Rex Waygood
 

Thanks Rex. I had read the explanation on the video the other way around. So the comparison shows what I encountered : 255,0,0 in Adobe RGB cannot be printed on paper.

No Adobe colourspace cannot produce the saturated reds, blues, cyans or magentas that your printer should be capable of printing. You need a wider colour space such as ProPhoto (or as Dan says Lab) to reach those colours.  Looking at my video AdobeRGB 255,0,0 is probably OoG on your printer but there are darker reds with a higher a Chroma. These printable reds using a wider colourspace may look more red than using Adobe RGB. Are you saying they are OoG because they look wrong to you when printed? It sounds like something is wrong somewhere. I think you should be assessing real images not made up colour squares. 

Does it make sense, to bring everything myself into gamut before printing? This in stead of letting the software decide where to shave corners. 

I recommend not letting the software bung things into gamut by using Intent. You are not in control doing that. So ensuring that the colours are in your destination gamut ensures you will get what you want and be in control.

It is starting to sound like you do have another problem but I would still suggest you try a troublesome image (not colour squares) using a wide gamut work flow. The only other suggestion I can make is that to check your printer you buy a custom profile. That would either identify you have a print problem, or fix it.


Rex Waygood
 

I've just twigged why (probably) your Adobe red 255,0,0 isn't your printer's best red. It is as you've realised you are allowing Intent to put that colour into your printer's gamut and as it is a long way out it will depend upon which Intent you have chosen as to where it ends up. I wouldn't expect it to be orange but it need not be an intense red. You could do a quick play with the various Intents or start producing colour squares that are in Gamut for your printer. You could produce a Granger Chart for your printer profile in PS and print that out. It would include the redest red your printer can produce. I'm off to bed :-)


Beat C
 

>> Rex wrote :
>> These printable reds using a wider colourspace may look more red than using Adobe RGB. Are you saying they are OoG because they look wrong to you when printed?

The 255,0,0 red in any RGB colorspace except sRGb gives me OoG when I look at the OoG warning in PS. The complete red square gets pink, which is my (and I believe default) OoG color indication.
I will try and go to a bigger Colorspace, although it feels very counter intuitive. IMHO : if the red is already OfG for the paper in Adobe RGB, it will be even more OoG in ProPhoto (or Lab). But I will try it out tomorrow.

>> I think you should be assessing real images not made up colour squares. 
I was using 'even coloured' squares as to see exactly what is happening. I will do the test tomorrow with a color test image.

>> I recommend not letting the software bung things into gamut by using Intent. You are not in control doing that.
I was thinking the same. Especially as the two most used rendering intents are pretty flawed in my opinion. If we would let the Rendering intents (software) take care of the bringing into gamut of colours, we should be able to choose with a slider between the two extremes (being Perceptual and relative Colorimetric). So an adjustable bit of both.

Rex, can you or someone else on the list explain to me why the bigger colorspace should work. I mean : I have a certain colour red (or whatever colour) that is OoG for the paper. Now I convert my file to a bigger Colorspace, which changes the underlying numbers, but not the color. Would the paper not still have exactly the same problems printing the colour? The paper does not know, nor care about the underlying numbers. Is there something in the translation from the bigger colorspace  by the printer (software) that makes the colour come out better?  I will try to do the test in print tomorrow, but I’d like to understand the reasons behind it.


>> I've just twigged why (probably) your Adobe red 255,0,0 isn't your printer's best red. It is as you've realised you are allowing Intent to put that colour into your printer's gamut and as it is a long way out it will depend upon which Intent you have chosen as to where it ends up. 

I don’t think it matters which rendering intent I choose, as  with a solid single color, both RI’s act the same. They both bring the red just inside the gamut of the paper. As there are no other colours to shift in relation, perceptual and Relative Colorimetric act here the same, I suppose. I have not confirmed by practice, this is my thoughts about it. I will include the test of RI tomorrow.

Beat


Michael Jahn
 


Granger Rainbow can be downloaded from here:

http://colorremedies.com/realworldcolor/downloads.html 

Third link down - good luck with the reds !

 
Respectfully,

Michael Jahn
2718 Cimmaron Ave
Simi Valley, CA 93065

805 416 6946


On Sun, Aug 25, 2019 at 12:24 PM Beat Cornaz b.cornaz@... [COLORTHEORY] <COLORTHEORY@...> wrote:


Rex Waygood
 

The 255,0,0 red in any RGB colorspace except sRGb gives me OoG when I look at the OoG warning in PS. The complete red square gets pink, which is my (and I believe default) OoG color indication.
I will try and go to a bigger Colorspace, although it feels very counter intuitive. IMHO : if the red is already OfG for the paper in Adobe RGB, it will be even more OoG in ProPhoto (or Lab). But I will try it out tomorrow. 
Rex, can you or someone else on the list explain to me why the bigger colorspace should work. I mean : I have a certain colour red (or whatever colour) that is OoG for the paper. Now I convert my file to a bigger Colorspace, which changes the underlying numbers, but not the color. Would the paper not still have exactly the same problems printing the colour? The paper does not know, nor care about the underlying numbers. Is there something in the translation from the bigger colorspace  by the printer (software) that makes the colour come out better?  I will try to do the test in print tomorrow, but I’d like to understand the reasons behind it.


You are correct that a larger colourspace will not allow you to print anything that is currently out of gamut. The gamut of your printer is fixed and the colourspace will not help extend that.
However Adobe RGB is smaller than the gamut of your printer including in the red area. That means that the software, or you, have more choices as to where to stick the OoG reds and indeed more reds are available. It will not help you in trying to achieve your dream red. It might help with a real picture retaining some detail in the red, and other colours.
I did download the profile for your printer and the Baryata 310 paper and did some experiments. One observation is that your printer paper combination is a lot better than mine but I have never felt that mine was inadequate. 

I don’t think it matters which rendering intent I choose, as  with a solid single color, both RI’s act the same. They both bring the red just inside the gamut of the paper.

I think you are probably correct. My experiments and my comment were relating to real images and Intent. PS Intent (RC & P) don't seem to quite behave as per guides like https://www.cambridgeincolour.com. Hence my comment about you taking control such that intent isn't needed. However the decision can be made when reviewing the content of your image, ie use RC or P or get it in the destination gamut yourself.  

I see Michael has given a link for downloading a Granger. They are easy to make. I made a red one when looking at your printer/paper performance.

In the colourspace that you wish to investigate create a blank canvas.
Choose the spectrum gradient and lay a straight gradient across the canvas.
Create a new layer and put an orthogonal black to white gradient down the paper.
Change layer mode to luminosity and you have a Granger.
To investigate your reds, I did the same but used a red to white gradient on the first layer. I then used the PS OoG check and found where Adobe 255,0,0 was. I did lots of other fun experiments too :-)

One experiment I did was to create a Granger in Red in your printer/paper "colourspace"/Gamut. That gave a surprising result but that might be my ignorance as I've never done it before for a printer/paper combination. 

I hope this helps. It is obviously difficult when your colour results are not visible to the rest of us. :-)
Rex



Dan Margulis
 

Beat writes,


>> 
Red does not have these advantages. The theory is that magenta ink prevents reflection of green light, and the theory is correct: magenta ink is quite efficient as compared to cyan. Yellow ink is even better, 
>> it almost totally prevents reflection of blue. Mix the two together, and they eliminate green plus blue, allowing only red light to reflect off the print. That there is also a red ink available may or may not help. 
>> If it’s a different hue than the “red” the user wants it could actually be harmful.

Dan, can you explain the last sentence some more?

In my Canon printer I guess that the Red id the RGB red (as are the Green and the Blue inks).

“RGB red” is an unknown concept. Every RGB defines “red” differently. Plus it might be advantageous to have a slightly lighter red than any of them. If Canon says that their “red” ink is 54L81a70b or 61L128a105b then we have specific information. But just calling the ink “red” could mean anything from the color of a tomato to that of a rose to something more pink. Or either one of the two enormously different LAB values above—which are, respectively, sRGB red and ProPhoto red.

So sending a square of 255,0,0 to the printer should deliver the right bright red. Alas, it doesn’t and it’s way off. Dull and dark on different papers with different profiles. Of course. I’ll resign if it just is not possible to get a bright red, but I’d like to understand why it fails. Red is an important colour and Canon would be stupid if it put in Red ink, that doesn’t deliver.

It isn’t stupid, the majority of the industry probably believes that dumping a red ink on top of a lot of magenta and yellow ink somehow produces a stronger red than otherwise possible. And there may be some printer-specific reason why a mix of RMY might handle better with respect to inkdrop distribution etc. But in principle having any kind of red ink available won’t give a much more saturated result than MY alone.

A blue ink, OTOH, is authentically helpful. So is a light blue, or a pink. If you have to do pink flowers a pink ink is more effective than MY alone. This is why those seeking to expand the gamut of offset printing have found that adding a light cyan and a light magenta is more effective than adding something strong like a red.

Dan, have you somewhere written about how to optimal  use and prepare for multi ink printers? Your detailed explanations of how to prepare for a CMYK press was very inspiring and useful for me. Is there something in that vein for modern inkjets?

No, because the user has much less control. The situations are analogous in the sense that extra inks give options. In standard 4/c the black is seen as a more or less equal combination of CMY. In an inkjet a red ink is seen as a more or less equal combination of M and Y. In either case it’s theoretically possible to balance the two sides for profit. A light gray, or a light pink, should contain very little of the strong (black, red) ink, but a much darker version should have a much higher percentage of K/CMY and R/MY. When the color is something in the middle the question is how rapid the transition should be to a higher percentage of the stronger ink.

In CMYK the user has a lot of control over this, for example if we have an image where it is unusually important to hold neutrality on press, we use more black ink and less CMY. But with an inkjet we’re at the mercy of whatever algorithm the designers have chosen. 

I just went to PS and made a document with squares of Red 255,0,0   Green 0,255,0    Blue 0,0,255. When starting with my normal Adobe RGB colorspace, all three are out of gamut on Canson Baryt paper.
The red gets an orange, the green a yellow green and the blue duller mostly darker, like the others as well. When assigning sRGB to the file, the colours get a bit duller and the Red is in gamut (G and B still out of gamut). When assigning ProPhoto, all get brighter and even more brilliant, and so even more out of gamut. 
So my conclusion is, that the greens and blues perform as good or as bad as the reds. I might have noticed it most with the reds..

You noticed it more because it’s more important to you. Once in a while you need a blue that approximates 0,0,255. A green that intense, almost never. But there are gangs and armies of images that require bright reds.

Does it make sense, to bring everything myself into gamut before printing? This in stead of letting the software decide where to shave corners. 

Only if you consider that you have better artistic judgment than some bucket of bolts. ;-)

Dan Margulis



john c.
 

Dan,
 
I agree that the goal of having red ink isn’t to increase gamut as much as it is to replace M+Y with a single ink to achieve a smoother dithering which would be most useful in areas like flesh tones. How a rip or printer driver knows where and when to make that substitution is often like alchemy, and if those curves aren’t handled well, I’m sure it could actually reduce the potential gamut in some shades of red. The last thing we want is too much ink or more than we need to make any color. In this case, using half the amount of ink to make a color has to be better than loading up the paper with two or more inks to make the same color, even if the gamut remains the same.
 
John Castronovo
 
 

Sent: Wednesday, August 28, 2019 10:24 AM
Subject: Re: [COLORTHEORY] Reds print worst on my Canon ipf6400
 

It isn’t stupid, the majority of the industry probably believes that dumping a red ink on top of a lot of magenta and yellow ink somehow produces a stronger red than otherwise possible. And there may be some printer-specific reason why a mix of RMY might handle better with respect to inkdrop distribution etc. But in principle having any kind of red ink available won’t give a much more saturated result than MY alone.
 


Beat C
 

>> Rex wrote
>> You are correct that a larger colourspace will not allow you to print anything that is currently out of gamut. The gamut of your printer is fixed and the colourspace will not help extend that. 
>> However Adobe RGB is smaller than the gamut of your printer including in the red area. That means that the software, or you, have more choices as to where to stick the OoG reds and indeed more reds are 
>> available. It will not help you in trying to achieve your dream red. It might help with a real picture retaining some detail in the red, and other colours. 

Thanks again Rex for your patience and endurance :-)  I can see your point. So if I understand you correctly, by converting to a larger colorspace, the translations will have more options to move the colours that are OfG into other shades, which would not be available in the smaller colorspace. So working in Adobe RGB is fine, but sometimes it is wise to convert in the end (after the editing) to proPhoto or Lab. 
Then do the taming (bringing back into gamut) of the colours there and then print. Makes sense.

As to the R.I. Of course with real images, there R.I. can make a big difference, but both (perceptual and Relative Colorimetric) have quite big disadvantages. That’s why I suggested an adjustable mixture of the two. But, as you state as well, better to take matters in my own hand, and bring the OoG colours with curves and / or desaturation within Gamut.

I downloaded the Granger. Thanks Michael. The recipe that Rex brings to table is very handy as well. I definitely will start experimenting with all this new stuff and ideas. It will be next week, probably, as I got an unexpected invitation to make a series for a local museum. In a rush, as most of the time.


>> Rex wrote :
>> I hope this helps. It is obviously difficult when your colour results are not visible to the rest of us. :-) 

It definitely helps and I fully agree. I get generally very good feedback on my prints, but just because of that, I want them to be even more perfect. And as I noticed my battle withy the reds, I thought it time to get the max out of my prints. The fun is in always improving, isn’t it. And along the way, one starts to understand the complete picture with all it’s interactions and relations better & better.

Regards, Beat


John M. Henry
 

I find this interesting, as printer with a two different color boxes, two large format printers and a 4 color press. All using different rips, One EFI, one creo, rasterlink and one Hq ctp. We work with G7 and our output is very consistent across platforms doing so. I can say the color if not kept in the workflow can be far different. Basically G7 dumbs down the output across the board for a more flat look press cmyk.

The Mimiaki can do the widest range, it even uses different ink sets. They now use orange to help with reds and flesh tones. Sadly their color management in (rasterlink) is not standard and costs an extra $4000 for a system that is subpar.
Cyan
Magenta
Yellow
Black
Light Cyan
Light Magenta
Light Black
Orange

We even play with the RGB input the profiles on the eif as we often so such different results on the files we get in. Like Dan said that profile conversion will have a big impact and even the year of the rip will have different ones. Very few rips can on theses unit give you the power to control it for all situations. Hell most of my customers have no clue what they send me or want to know.



John M. Henry

Speedway Press • Mitchell Printing & Mailing Inc. •The Phoenix Press
1 Burkle Street
Oswego NY 13126
315-343-3531

Founding Board Member National Print Owners Association



John@speedwaypress.com

You can now pay your invoice securely, easily, online at the following link:
https://mxmerchant.com/mxcustomer/d/478d3195-107a-49d5-9d2a-080fc0338a66/v3


Rex Waygood
 

I can see your point. So if I understand you correctly, by converting to a larger colorspace, the translations will have more options to move the colours that are OfG into other shades, which would not be available in the smaller colorspace. So working in Adobe RGB is fine, but sometimes it is wise to convert in the end (after the editing) to proPhoto or Lab. 
Then do the taming (bringing back into gamut) of the colours there and then print. Makes sense.

If you wish to exploit the full gamut of your printer then it is best to have a workflow that uses a colourspace that encompasses all you destination/printer gamut. For your excellent printer that would probably be ProPhoto (or as Dan said Lab).

Converting from Adobe to ProPhoto means you may well have used intent to put colours in your image into Adobe colourspace, they are not then recoverable by going to ProPhoto. 


Dan Margulis
 

John Castronovo writes,


I agree that the goal of having red ink isn’t to increase gamut as much as it is to replace M+Y with a single ink to achieve a smoother dithering which would be most useful in areas like flesh tones.

By “replace” I trust you mean “reduce the amount of” rather than “eliminate totally”. If so, we’re on the same page. The less white paper that shows through, the better depiction of continuous-tone. This is why when mixing grayscale and color in commercial printing, people separate the grayscale into CMYK, the appearance seems smoother and more in line with the color images. In an inkjet printer the effect wouldn’t be nearly as strong but technically it exists.

The bigger advantage of using lesser amounts of three inks as opposed to greater amounts of two is in calibration/QC. If there’s anything slightly wrong with, say, the magenta ink or the printer’s function with respect to it, then RMY might give an acceptable result and MY not. Similarly, printing R only would be subject to quality issues if there was anything wrong with the red ink, whereas we might be able to get away with RMY.

Dan Margulis




john c.
 

Yes, we’re totally on the same page. Reduce not replace.
 
John Castronovo
 

Sent: Thursday, August 29, 2019 8:48 AM
Subject: Re: [COLORTHEORY] Reds print worst on my Canon ipf6400
 


John Castronovo writes,


I agree that the goal of having red ink isn’t to increase gamut as much as it is to replace M+Y with a single ink to achieve a smoother dithering which would be most useful in areas like flesh tones.
 
By “replace” I trust you mean “reduce the amount of” rather than “eliminate totally”. If so, we’re on the same page. The less white paper that shows through, the better depiction of continuous-tone. This is why when mixing grayscale and color in commercial printing, people separate the grayscale into CMYK, the appearance seems smoother and more in line with the color images. In an inkjet printer the effect wouldn’t be nearly as strong but technically it exists.
 
The bigger advantage of using lesser amounts of three inks as opposed to greater amounts of two is in calibration/QC. If there’s anything slightly wrong with, say, the magenta ink or the printer’s function with respect to it, then RMY might give an acceptable result and MY not. Similarly, printing R only would be subject to quality issues if there was anything wrong with the red ink, whereas we might be able to get away with RMY.
 
Dan Margulis