How to know if your printer is clueless when you're clueless too?

meddington

Well-known member
Complete Color management in commercial printing is a holy grail, for now. (I know that's asking for trouble on this forum, but there is some truth to it from a practical standpoint.)

I don't necessailry disagree with you, but I don't think its unreasonable to have specific questions regarding the workflow and rip settings answered.

My practical advice? Get a one-off proof and and adjust your monitor to match it. Then adjust color and resend files if need be.

Obtaining a one-off proof is great advice, but how are you suggesting to adjust the monitor towards the proof? Easiest way would be from a profile of the device that generated the proof...in fact thats the only way I would recommend.

If you don't have the budget, send a deskjet proof that you like and ask them to do the best they can. Printers will bend over backwards to help you if you don't drive them crazy.

Representing the printer, there's not much I hate more than an un-verifiable proof that we're to "match" This will drive me crazy faster than any color management inquiries. And if the printer has taken the time to properly set up their workflow, there's usually a lot less bending over that needs to occur.
 

meddington

Well-known member
We do not honor embedded profiles on our Indigo 5000, its alot easier to have Colour Management at a device level instead of it being in your customers control. Which isn't always going to be right.

There's not necessarily anything wrong with not honoring embedded profiles, so long as the client has been made aware and instructed on how to optimally prepare files for the device.
 

Mark Flanders

Well-known member
good points.

On reasonable questions) The fellow didn't like the answers he got and suggested that they were clueless. (Though the printer saying the profile is secret IS very silly.)

On ballparking color) You are probably right, and I admit it's crude, but the problem with getting a profile of the output device is that it doesn't do anything to calibrate the customers monitor.

on matching deskjets) Agreed. Especially if it's a 6 color print. But this fellow wants his blue antarctic highlights, and he should communicate this in some way if it's critical.

thx!

mf.
 
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PDeuth

Active member
I Googled HP Indigo ICC profiles and got this link:
Bonsai Photography - Home
I downloaded the profile and installed it, checking it in ColorThink Pro. The Indigo gamut matches pretty well with the Fogra 27 Coated gamut. It is hugely smaller (27% the size), and of different shape, than the Adobe 1998 gamut. What looks good to you on your monitor won't look the same when printed on the 5000.
May I ask why you want to print with a digital press? Is it a short run you're after? The color variation on a digital press is large, much more than offset litho - and that's a highly variable process, too. If your job is color-critical, think about printing more than you need and weeding out the unacceptable copy through 100% inspection.
Have the printer send you a proof, or install that profile somewhere there is an inkjet, a color-managed inkjet, which you can use as a proofer, and see what you get. Or, if your monitor is calibrated, soft proof using the Indigo profile in Photoshop; the proof is better, however, easier to see. Be prepared to live with some trade-offs. If you're shooting in a studio, keep your contrast low by using diffuse lighting. If you have extreme saturation and high contrast, be prepared to lose much of it. As long as the tonal relationships are maintained in the reproduction and the printed piece is attractive, you should be happy. On the technical side, I agree with those who support using Rel. Col. as a rendering intent. The white point compensation works well, and we still have "issues" with the Perceptual intent.
The jpeg is a comparison of the Indigo profile with the Fogra 27 Coated. The Fogra is the wireframe and the red 2D gamut, at L* = 50, below. I showed the area of the greatest difference. Heck, I'll post a comparison of the Adobe and the Indigo in another reply.
 

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PDeuth

Active member
Here are two more images, comparing the Adobe 1998 RGB color space with the Indigo destination profile space. Look how much you'll lose, especially in the Blue regions. If you have a bright, satruated blue in your photo you love, you might miss it in the reproduciton. The trick is not to get surprised. Good luck, welcome to the world of color reproduction.
 

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prepresscolor

Well-known member
Printing you photography to a book!

Printing you photography to a book!

Well, I guess it depends on whether you are more interested in saving money or having a quality product.
The printer you have choosenand the questions you have sound like you are into a small budget. If not you would be using a conventional Sheetfed, Commercial Printer who would steer you right.
Think about this, why would any "sheetfed printer" ask you to use a Standard Web Ofsett Profile (SWOP)?
Secondly a good printer would take at least "some" time with you to ensure the project progressed well, if they are going to accept RGB files then they should know that ADOBE1998RGB.icc is the largest color gamut for RGB and would be the best for your to work in for your photos but, if they are printing in CMYK only then they should provide you with their "press profile" so you could adjust your images for the tonal and contrast losses which CMYK offer.
 

FlightDeck

Active member
(Please forgive me if I slip too far into rant mode. All due respect all around.)

Marko, thanks for the comments/rant ;) I understand the practicalities as well, however as you've probably noticed, opinions among users and operators here and elsewhere very incredibly. Such is the fun of colour management... Also please don't interpret that I've a low opinion of a company because they are a new start-up (which, by the way, they are). I'm just proposing that it may explain some of the lack of confidence-inspiring answers I've received from this one particular shop.

My practical advice? Get a one-off proof and and adjust your monitor to match it. Then adjust color and resend files if need be.

This is probably where I'll end up. Get a print, compare it to the monitor, adjust to match, and re-print. However do you appreciate the irony of this approach? ;) This is essentially printing profiling, and exactly what I'm asking the printer for. If only someone had already done this, and could simply provide me the colour profile, and all their other customers, to save us having to spend time money on it ourselves. Great idea! :)

In the end, this lab has apparently decided they're not interested in my business, as I haven't received a response to my final inquiry in nearly two weeks. I've since started evaulating other shops that look more promising.

The saga continues...
 

FlightDeck

Active member
The fellow didn't like the answers he got and suggested that they were clueless.

I didn't suggest they are clueless. I asked how I would know, when I'm not very familiar with that end of the business myself. Which is why I'm here for second opinions :)

On ballparking color) You are probably right, and I admit it's crude, but the problem with getting a profile of the output device is that it doesn't do anything to calibrate the customers monitor.

I'm not following your point here. The output device *shouldn't* do anything in regards to monitor calibration. That's what my calibrated monitor profiles are for.
 

FlightDeck

Active member
May I ask why you want to print with a digital press? Is it a short run you're after?

I have no preference. (I know, GASP! ;)) The reality is, as another poster mentioned, I'm dealing with very small volume (less than 10 probably), and thus low budget, which has me in the mass-market photobook producer arena. If I knew of other "more-capable" suppliers within this budget range in my area, I'd happily check them out, however I simply do not know where to find one.

Many thanks for making the profiles comparisons for me. I know there's a huge loss going down to CMYK. The comparison I'm looking for is comparing the US SWOP Web-Coated v2 they recommended with something like an Indigo 5000 profile (assuming it's reasonably decent), so I can compare how things might shift if I'm using SWOP v2, i.e., how far off might I be by using it.
 

meddington

Well-known member
The color variation on a digital press is large, much more than offset litho - and that's a highly variable process, too.

Although this certainly can be true in some instances with some digital print devices, the Indigo (and others) can be a very stable printing device. I would put the stability of our indigo well above offset litho.
 

meddington

Well-known member
If I knew of other "more-capable" suppliers within this budget range in my area, I'd happily check them out, however I simply do not know where to find one.

Dude...we'll happily quote your project. contact me off-forum (meddington@nac-mi.com) or PM me if interested.

Many thanks for making the profiles comparisons for me. I know there's a huge loss going down to CMYK.

Depends on the image really...just because an image is tagged with AdobeRGB doesn't mean it utilizes the entire gamut. More often, there is little visual shifting upon conversion. And again, many monitors can't display an AdobeRGB, so the loss may largely be invisible. Plotting image data against the gamut in ColorThink can be useful here.

The comparison I'm looking for is comparing the US SWOP Web-Coated v2 they recommended with something like an Indigo 5000 profile (assuming it's reasonably decent), so I can compare how things might shift if I'm using SWOP v2, i.e., how far off might I be by using it.

Just remember the difference between assigning and converting profiles when softproofing. Though the device profiles may be different, image integrity can be maintained through conversion.
 

FlightDeck

Active member
An update and some new questions

An update and some new questions

Hello all,

Once again many thanks for all the info provided in this thread. Many weeks have now passed and I have some new questions, as well as an update. Some of this is no longer related to colour management, but to keep things together I figured just continuing this thread makes the most sense.

I checked out some other print shops, however as all were in the USA, which carries a 30% mark-up due to currency exchange and high cross-border shipping costs, unfortunately none were viable options.

I met in person with reps from the Canadian printer that was discussed here earlier, viewed samples, etc. They offered to run some proof pages from my project. Their instructions remained to soft-proof with the US SWOP Web-Coated v2 profile, using Relative Colorimetric rending intent. I ordered 2 proof sets, one on their "satin" paper, and one on "matte" (I don't know the specific stocks).

When the proofs arrived, potential flaws in the above approach became immediately apparent. First, both sets have a significant magenta cast, particularly across what should be neutral greys. The satin suffered this more than the matte. Next, the white point of the satin paper is considerably more yellow than the matte (which was stunningly "white"). This meant a B&W image on satin was more magenta and yellow.

The exercise pretty much validated all the preceeding discussion that trying to soft-proof this with one canned profile has limited utility. Further, if the lab is not taking care of the necessary colour adjustments to match the input in the absence of tailored colour profiles, then odds are high you don't get (reasonably close to) what you'd like.

They are going to re-run the proofs with some adjustments, primarly to bring down the magenta cast. They remarked the magenta ink they use is very "strong" and they've had issues before with projects coming out too magenta, particularly for B&W photographers. That in itself seems to contradict their prior claims that their colour control is excellent, they calibrate continuously, etc., etc. I think the reality is they print what they get and they wait for a customer to point out an issue before they'll put any time into checking the colours. (I should also note that, having met their staff, this is a very young / inexperienced shop.)

So assuming they can adjust their process to adequately match the files I've sent them, I'll be happy. I should know next week when the new proofs arrive.

Any comments on this magenta issue? I realize that "black" is difficult to produce with ink, and that colour casts are sometimes encountered. I'm just curious how often it occurs, or should a shop with a good process already have it well under control?

On to new questions...

I noted the proof images were grainy when viewed casually from normal distances. I'm not expecting photographic-print quality from this process, but I was surprised how readily notieable this grain is. After confirming this wasn't in the original images, I believe what I'm seeing is the linescreen resolution of the printer..., the ink "rosettes".

Their website claims they halftone at 180 lpi. Is this about right for the hp Indigo 5000 series? Further, they request the images be put into their PDF-making software at 240 dpi, which is exactly what I gave them, no more no less. Is 240 dpi adequate? Put another way, could I get less perceived graininess by providing higher, say 300-400 dpi? Noting it will be considerable effort for me to re-generate the PDF at higher dpi, where is the point of diminishing returns?

Would stupid amounts of sharpening have bigger benefit?

I also note this rosette grain is visible in text elements. As they are uniform colour, it shows up more as jagged edges, even on straight vertical and horizontal lines. (This makes sense, as a magnifying glass inspection shows that the rosettes are in a sort of hexagonal grid, and not aligned to page-edges..., presumably to minimize other issues/artifacts.) Based on that, my above suggestion to increase dpi on the images may not have any effect if even text is grainy/jagged.

While I know this is difficult to discuss without seeing samples, what is the best I could expect from this print equipment? What would be an optimum image dpi to provide it?

I qualitatively compared the rosette size to some other printed products. A similar "micro-published" photography book, a commercially-produced photographic magazine, and some high-quality travel brochures all appeared to be about the same rosette size as my proofs. (They seem less grainy at normal viewing distance, but maybe I'm just more sensitive to my own images, having already seen them as photographic prints.) A commercially-produced photographic book however appeared to have no rosettes at all (unless they were stupid tiny)..., would that be from an offset press instead?

Thanks and regards,
KDJ
 

Sherbert

Well-known member
At 180lpi, which is fine for the indigo you should be able to get 360dpi. Are you sure they don't mean 360dpi and not 240dpi?
 
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FlightDeck

Active member
At 180lpi, which is fine for the indigo you should be able to get 360dpi. Are you sure they don't mean 360dpi and not 240dpi?

Their instructions specifically state 240 dpi.

I recally reading once that there is an optimum 2:1 ratio, that you can provide a dpi that is twice the printer's lpi, but any dpi above that does not provide additional benefit. From your comments it sounds like this is indeed true?

If that's the case, then my providing them only 240 dpi means I am down a full third in linear resolution, and have only 45% (0.67x0.67) of the optimal area resolution, obviously very significant, and might explain why it's so noticeable.

So do you think there will be significant increase in the the print results if I up everything to 360 dpi for this printer?

Thanks and regards,
KDJ
 

Mark Flanders

Well-known member
Hello again,

(I'm the commenter who suggested that total color control is unrealistic. Forgive me my flaws.)

- Color:
I often have a magenta cast on my first off Indigo proofs, and adjust accordingly. There are excellent custom color controls on the indigo if you have something to go by. However, if you're printing Black and White photos ... which are apparently not grayscale, but RGB, converted to CMYK, then you are actually printing quad-tones. (I'm showing my age here) Anytime you print a b/w photo in four color, even the smallest shift will create a color cast. (You know this from your neutral gray photography work, where there is a much more established and contained color control environment) Quad tones look great, in my opinion, but the effect is similar to a duotone, and good detail, but will have a rosette. If you want no color or rosette, then make the images grayscale.

Line Screen/DPI

This one makes me wonder if you might be right about the shops inexperience. 180 line? 240 DPI? That's a little odd.

My Indigo, which is older than the 5000, prints a 175 line screen, and has the option of 195 line and 230 line. I generally use 175. If your images have lots of busy detail, the 230 line screen might look fantastic. Be careful of images with large areas of light-medium and gradient tones...like an open sky sunsets. Electronic banding can occur and will show in the higher line screens.

So far as DPI, you are generally correct in the 2:1. Maybe they have some odd automation, but I would recommend sending files no less than 300 dpi, but not more than 600.

Also, if your text has screening, than you have 'rasterized" your text and the RIP is treating your text as grayscale/Color instead of line art. You really shouldn't set type in photoshop, but in a page layout program like InDesign or Quark, or conceivably in Illustrator. (MS Publisher if you must) Embed fonts, or convert to outlines, but don't rasterize them. (A font file is a mathematical description of the shapes of the letters, and is not dependent on resolution to look good. Rasterizing is essentially turning it into a picture file, which solves the missing font problem with a sledgehammer. Place your pictures, set you text, and export high quality PDF with fonts embedded...this is the basic approach. If you must set type in photoshop. see if you can save a TIFF with unrasterized layers.

Good luck!

Mark
 

FlightDeck

Active member
- Color:
I often have a magenta cast on my first off Indigo proofs, and adjust accordingly. There are excellent custom color controls on the indigo if you have something to go by. However, if you're printing Black and White photos ... which are apparently not grayscale, but RGB, converted to CMYK, then you are actually printing quad-tones. (I'm showing my age here) Anytime you print a b/w photo in four color, even the smallest shift will create a color cast. (You know this from your neutral gray photography work, where there is a much more established and contained color control environment) Quad tones look great, in my opinion, but the effect is similar to a duotone, and good detail, but will have a rosette. If you want no color or rosette, then make the images grayscale.

Hi Mark,

I was probably ambiguous..., I'm not printing B&W myself, I'm doing colour, though some of the images border on duotone due to the landscape I was shooting. I mentioned B&W only as an example where I would imagine people would be incredibly picky about the magenta cast, and since this company's majority of clients are probably wedding photogs, they would get a lot of B&W orders.

I'm glad though that you mention they have good colour controls if they have something to "match"---I've sent them electronic images (although they already have this in the PDF), and they are going to try that.

Line Screen/DPI

This one makes me wonder if you might be right about the shops inexperience. 180 line? 240 DPI? That's a little odd.

My Indigo, which is older than the 5000, prints a 175 line screen, and has the option of 195 line and 230 line. I generally use 175. If your images have lots of busy detail, the 230 line screen might look fantastic. Be careful of images with large areas of light-medium and gradient tones...like an open sky sunsets. Electronic banding can occur and will show in the higher line screens.

So far as DPI, you are generally correct in the 2:1. Maybe they have some odd automation, but I would recommend sending files no less than 300 dpi, but not more than 600.

I hadn't heard about the banding at higher printer lpi, thanks for the heads up about that. I assumed that most of the printers were keeping the hp 5000 down around 180 lpi instead of up at 230 lpi just to print faster and/or avoid quality issues that could arise at the "edge of the envelope".

I went ahead and mentioned to the shop that I was getting feedback (here) that 240 dpi might be too low to get optimum results, and I should maybe go as high as 360 dpi. Their reply? They felt "300 dpi is the standard and recommended value". !!!! But their instruction says to use 240 dpi!! :mad: I pointed that out and didn't get a response yet. Anyhow, they are going to re-run the proofs with higher dpi as soon as I provide them. I'm hoping that provides the noticeable reduction in "graininess" that I perceived in the 240-dpi set.


Also, if your text has screening, than you have 'rasterized" your text and the RIP is treating your text as grayscale/Color instead of line art. You really shouldn't set type in photoshop, but in a page layout program like InDesign or Quark, or conceivably in Illustrator. (MS Publisher if you must) Embed fonts, or convert to outlines, but don't rasterize them. (A font file is a mathematical description of the shapes of the letters, and is not dependent on resolution to look good. Rasterizing is essentially turning it into a picture file, which solves the missing font problem with a sledgehammer. Place your pictures, set you text, and export high quality PDF with fonts embedded...this is the basic approach. If you must set type in photoshop. see if you can save a TIFF with unrasterized layers.

They claim they use vector text all the way through, and it appears that's the case. Submissions are made via their own PDF-making software, which is what I used for all of the text. I did not provide any as an image, so if there is any rasterization occuring, it's in their pre-press process.

Normal-size black type is incredibly crisp. However larger sizes, which I have as blue on white, grey on white, white on black, and white over image, are noticeably jagged. The white on black appears the sharpest. Grey on white is probably the worst, and white over image isn't great either.

It almost makes me suspect they might not even be at 180 lpi...

Thanks,
KDJ
 

meddington

Well-known member
It is my understanding that the default screening on the 5000 is approx 144 (sequin) and that the higher linescreens are not true lpi, but "simulations" or interpolations of the intended lpi (this has been indicated to me from HP techs).

Asbd altough the 2:1 ratio of dpi to lpi is good practice, 1.5:1 often is sufficient. In short, I don't think you'll see a significant improvement from 240dpi to 300dpi, particularly on the indigo. Also note that if the linescreen is changed on the indigo, there could be color differences from the same file at lower linescreens unless thr printer has compensated for this via curves or colormanagement.


Further on graininess, the dot shape from the indigo is a bit irregular compared to a comparable offset Litho dot. A bit ameoba shaped in fact, and this lends itself to gradients that are not quite as smooth, particularly at higher percentages where the dots begin to connect. Noise added to the gradient helps.

Further on type crispness, anything other than solid, pure channel text can have edge artifacts from dot shape and screen angle. You could try the HP adaptive halftoning feature. This can add a "halo" of sorts around the edge of the text which can help minimize edge artifacts.
 

FlightDeck

Active member
It is my understanding that the default screening on the 5000 is approx 144 (sequin) and that the higher linescreens are not true lpi, but "simulations" or interpolations of the intended lpi (this has been indicated to me from HP techs).

Hi meddington,

This wouldn't surprise me, as even on HP's early consumer laserjet printers they were always playing with "non-linear" approaches to emulate higher effective resolutions.


Asbd altough the 2:1 ratio of dpi to lpi is good practice, 1.5:1 often is sufficient. In short, I don't think you'll see a significant improvement from 240dpi to 300dpi, particularly on the indigo. Also note that if the linescreen is changed on the indigo, there could be color differences from the same file at lower linescreens unless thr printer has compensated for this via curves or colormanagement.

Through some on-line research I've found similar now myself, that 1.5 to 2 is acceptable. Apparently the 2 was more intended for follks making prints from scans and applies less to direct digital photos. In any case, I'll do a proof set at 300 and/or 360 dpi to see if there is any noticeable improvement for my particular images, and if no, then I'll leave them all as 240 dpi as they are now.

It may very well be that I'm at the limit of the envelope for expectations from this printer. Perhaps what I should do is try to avoid page elements that are most affected by resolution. For example, avoid light-gray text on white and stick to darker text. For white text over a photo, I could try to keyline the text in black (if possible with the software tools I have available).


Further on type crispness, anything other than solid, pure channel text can have edge artifacts from dot shape and screen angle. You could try the HP adaptive halftoning feature. This can add a "halo" of sorts around the edge of the text which can help minimize edge artifacts.

When you say "solid, pure channel", do you mean CMYK colour channel? I.e., pure black would be okay, but most any other shade/colour won't be because it's a mix of multiple colour dots instead of just the one? I think though that even for "black" this printer mentioned they use about a 70/30 mix with cyan.

Thanks,
KDJ
 

meddington

Well-known member
When you say "solid, pure channel", do you mean CMYK colour channel? I.e., pure black would be okay, but most any other shade/colour won't be because it's a mix of multiple colour dots instead of just the one? I think though that even for "black" this printer mentioned they use about a 70/30 mix with cyan.

Thanks,
KDJ

Any time text is screened, there is the possibility of jagged edges, and the lower the linescreen, the more obvious they become. Screen angles of 0 or 90 degrees would be better than say 15 or 75, where dot alignment and spacing can appear inconsistent along a vertical edge. Adaptive halftoning helps to fill those perceived gaps for a crisper edge.
 

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