What are my CMYK options ?.

You either need to get something like Photoshop to convert or have the shop do this for you which may be a better option. Converting to CMYK is easy (just select the option) BUT, it's a super critical function and CMYK is highly device dependant meaning you must use the proper conversion process (specified by an ICC profile). If you don't do this correctly, your output could be awful and that's an expensive mistake. So yes, Photoshop can do the conversions but do you have the propre ICC profile from the print shop? Will they supply it?

This might help too:

http://www.ppmag.com/reviews/200703_rodneycm.pdf

bitm07 wrote:

 

The problem appears to be that I supply the original files in the RGB color space, but they print using CMYK.

 

This is not really the problem. It is quite common hat printers get RGB embedded images (most widely used is  Adobe RGB) and have to convert to CMYK. The problem in your case seems to me that these printers do a lousy job in converting to CMYK.

As Andrew Rodney has already pointed out, CMYK is device specific, i.e. You have to convert to the CMYK color space specific for each printing machine by using the icc profile for this machine - and the paper used.

Converting to a general CMYK color space won't do much good. What you could do is ask the printing company for their icc profile and use this profile to convert your images in Photoshop CS. Lr cannot deal with CMYK, so there is no possibility to convert - or even softproof - to CMYK in Lr.

Having said that, the blues are a very difficult color to print (in offset CMYK printing) because of the inherent weakness (lightness) of the Cyan ink. The blues that you see in an RGB image (on screen) can probably be never matched in CMYK offset printing.

If they messed up your RGB files they're equally likely to mess up CMYK files. I agree with web-weaver that RGB or CMYK is not the issue here, and I also agree with Andrew Rodney that final CMYK separation is risky business unless you know what you're doing.

In short, submit RGB. If results aren't satisfactory, go somewhere else. RGB is the generally recommended way to go nowadays. A CMYK profile to proof to can be a big help, but aside from that leave CMYK to prepress.

I regularly send out Adobe RGB for books, magazines, posters, banners and whatnot, and nearly always get back a dead match to what I see on screen. But that's because the people "downstream" know what they're doing.

I currently do all of my layout work with Adobe InDesign using LR exported ProPhoto RGB placed images. REASON: I create wide-gamut RGB PDFs and eBooks of every "printed" book. CMYK placed images would unnecessarily limit the gamut in these screen-viewed electronic media books. I have had zero problems submitting CMYK printer profile converted PDFs to Blurb and other printers, and sRGB JPEG output to Costco.

I agree that the fault probably lies with your printer's processing workflow. The other possibility that could be causing these color errors is an uncalibrated or incorrectly calibrated montior.

trshaner,

Just curious: Are you using the Blurb icc profile to convert images to CMYK for Blurb?

Andrew Rodney and I discussed this in another post. I am using the one (1) Blurb.icc CMYK printer profile that Blurb makes available. I apply it inside InDesign using the Blurb PDF X-3 Export Preset v1-1 with Output> Convert To Destination (Preserve Numbers)> Working CMYK - Blurb_ICC_Profile.icc. I questioned Blurb Tech Support and here is their response:

Thanks for your question about why Blurb offers only one profile for five paper types.

Blurb currently offers five different paper choices for your books. We felt that trying to supply a Color Profile for each of the substrates would be confusing for some users. Instead what we have done is have our printer calibrate and target their printing device directly to our single Blurb ICC Profile against the paper type chosen during checkout. This takes any confusion out of the equation while still providing the most advanced color management available for a Print-On-Demand workflow.

What Blurb apparently does is to apply "additional" corrections based on the target paper during the RIP. Andrew and I both agree you can't soft proof acurately unless the exact paper type profile is provided. I have only used Blurb's Standard paper, which is 80# coated. I ordered the Blurb paper swatch kit with five paper types each printed with the same test image. The only paper where the printed image looked different was the Proline Uncoated, and that was only slightly lower in  contrast (as expected). The major difference is weight (80#, 100#, and 140#), which primarily affects opacity (see-through). My guess is the additional correction applied at RIP for paper type is very slight, with the exception of the Proline Uncoated.

Thank you trshaner.

I recently made a Blurb book on their Proline Pearl Photo paper. The results were excellent. I did not even softproof much since the images were B&W, some of them tinted. Just made sure that my shadows showed detail. Made the book in Lr5 beta and uploaded it from there to Blurb. Before uploading to Blurb I exported PDF's from Lr 5 beta with various sharpness settings to make sure that the sharpness is enough but not too much.

I contacted Blurb about this and they confirmed that sharpness can be "proofread" by exporting a PDF and inspecting it in Acrobat.

I take it that you are aware that the sharpness that Lr applies on upload in Blurb cannot be tested / made visible in Lr itself.

I use LR's Export module for resizing my images to 300dpi for placement inside InDeign. The Matte Paper> Standard sharpening is perfect for Blurb's Standard 80# coated paper. For previewing on screen just remember that the image should appear slightly over-sharpened for offset printing.

bitm07 below is a ColorChecker with sRGB profile (left) and a soft proof (right)  with Blurb CMYK offset printer profile applied. As you can see the dark blue and sky blue patches are the least correctly rendered due to smaller gamut of CMYK printing. There are some things you can do to get this closer, but as Andrew Rodney pointed out you will need Photoshop's CMYK soft proof and profile conversion tools

I just wanted to point this out so you know what to expect concerning accuracy of deep blues in your offset printed materials.

Thanks trshaner, I know about slighty over-sharpening. But is Blurbs printing process offset printing?

They say they use a HP indgo printer.

I looked HP indigo up. It's a process that emulates traditional offset printing through electronic means. Wikipedia writes:

"The technology is based on HP ElectroInk, which uses small colour particles suspended in Imaging Oil (Isopar) that can be attracted or repelled by means of a voltage differential. The ink forms a very thin and smooth plastic layer on the paper surface. The fact that these particles are so small ensures that the printed image does not mask the underlying surface roughness/gloss of the paper, as can be possible with some toner-based processes, bringing Indigo printing closer in appearance to conventional offset lithography, whereby ink is actually absorbed into the paper."

web-weaver wrote:

 

I looked HP indigo up. It's a process that emulates traditional offset printing through electronic means. Wikipedia writes:

"The technology is based on HP ElectroInk, which uses small colour particles suspended in Imaging Oil (Isopar) that can be attracted or repelled by means of a voltage differential. The ink forms a very thin and smooth plastic layer on the paper surface. The fact that these particles are so small ensures that the printed image does not mask the underlying surface roughness/gloss of the paper, as can be possible with some toner-based processes, bringing Indigo printing closer in appearance to conventional offset lithography, whereby ink is actually absorbed into the paper."

This may explain why there isn't much difference in appearance of the actual printed image on different paper types. ERGO–Very little difference in the paper specific printer profiles–but it's still limited to the four inks CMYK gamut. Apparently HP Indigo printers have wide-gamut capability using six or more color inks similar to  wide-gamut inkjet printers, which none of the digital print houses seem to offer. Here's a paper that discusses this capability:

HP-Indigo Technology and its Application to Photo Printing

On page 3:

Beyond the four process colors

While HP indigo presses brings high quality with four process colors, spanning ISO 12647 color gamut and reaching the darkest colors, they can also utilize up to three additional colors.  Light Cyan and Light Magenta inks for photo-realistic imaging. The light inks reduce granularity, providing smoother images and tone transitions, and a true photo look and feel. The white ink can be used for special applications, such as printing on black papers. IndiChrome enable enhanced color gamut.

trshaner wrote:

This may explain why there isn't much difference in appearance of the actual printed image on different paper types. ERGO–Very little difference in the paper specific printer profiles–but it's still limited to the four inks CMYK gamut.

I'm not buying that <g> and I have a lot of output from many Indigo's (there are different models and possible behaviors) and the dE differences based just on the paper (which can have huge amounts of OBAs) can be significant.

Blurb sent me paper samples initially. There are 5. For grins I measured them with the EyeOne Pro-2 (which worked fine using the older PMP ColorPicker which was nice).

Standard: 94.9/1.16/-2.63

Premium Luster: 96.7/1.85/-5.62

Premium Matte: 96.11/1.73/-5.77

Proline Pearl: 95.3/1.54/-4.20

Proline Uncoated: 97/1.93/-6.44

These guys like papers with high OBAs!

I loaded the Blurb ICC profile (seems to be GRACoL2006 Coated1, right down to the paper white. They're essentially using a copy of the IDEAlliance GRACoL profile and has little to do with how they're actually printing) into ColorPicker and the worst dE 2000 report for just paper was for Proline Uncoated with a dE of 3.8. Standard had the lowest dE at 1.2 with the others in the three’s.

A lot of what Blurb writes about color management in terms of it's process, using a single profile etc, is basically a load of CMS BS if you will.

Bet they are having everyone convert to GRACol (or it's done on the fly), then they use maybe a Device Link or maybe something like Oris to convert to the CMYK for each press behavior?

Thanks Andrew, much appreciated. I agree with you, Andrew and I both agree you can't soft proof accurately unless the exact paper type profile is provided."

I only have experience with Blurb books printed on the Standard 80# coated paper, so perhaps this one (1) paper type closely matches the Blurb.icc profile? Andrew can you explain the posted readings for the five paper? How much difference would you expect to see using the one (1) Blurb.icc profile soft proof as the reference? Like web-weaver I didn't find it necessary to make adjustments to the images based on CMYK soft proofing in PS with the Blurb.icc profile. I did adjust the images in LR more carefully concerning establishing good White and Black point settings and shadow area detail, but no changes to any color settings.

I did place a large image of a profiled ColorChecker PassPort image (without soft proof adjustment) on the last page of one book. All of the patches were very accurate when compared to the actual CCPP side-by side, except the Blue and Purplish Blue patches (as expected). In fact they were actually slightly better than the PS soft proof view using the Blurb.icc profile. I have no complaints with the color and tone accuracy using Blurb's Standard paper, even with no soft proof adjustment. I've only printed 8" x 10" standard portrait books, but the images are large enough to evaluate sharpness, color, and tonal rendering.

Andrew can you explain the posted readings for the five paper? How much difference would you expect to see using the one (1) Blurb.icc profile soft proof as the reference?

Those are LAB values for each paper. As you can see, they vary a lot! And this is just paper, not other areas of the device that can change. The dE differences in just paper white between measured paper and Blurb profile was as bad as nearly 4! So the papers alone are different from each other and the papers themselves are all different. What this illustrates is the need for 5 profiles not one. Five profiles that actually define the paper and the printer conditions. None of this appears to be how they are handling the process. Again, I suspect they are treating the CMYK GRACol profile like shops that demand sRGB. They probably do a CMYK to CMYK conversion depending on what paper (and printer) the job goes to. This is actually a bit worse than that sRGB workflow.

I'd expect a soft proof using a CMYK profile to be closer than not but this doesn't let them off the hook in supplying a profile that isn't remotely describing the print process. So instead of trying to aim an arrow to hit the side of a barn, what we have is a process where we attempt to aim an arrow to hit the front of the barn. Less bad, still not good.

Thanks Andrew. I went back and evaluated the five paper samples in the Blurb Sampler pack. I completely forgot that the test image printed on each sample is monotone (B&W). Here's my eyeball evaluation using a 5,500K viewing lamp:

Standard: Very slight shift to SEPIA (reddish-brown) tone with good shadow and highlight detail.

Premium Luster: Very slight shift to GREEN with good shadow detail and slightly higher highlights.

Premium Matte: Moderate shift to GREEN with very good shadow detail and good highlight detail.

Proline Pearl: Moderate shift to SEPIA (reddish-brown) tone with good shadow and highlight detail.

Proline Uncoated: Pronounced shift to SEPIA (reddish-brown) tone with good shadow and highlight detail.

Since Blurb printed these samples using their own color management workflow system I would assume this is what you can expect to see. Interestingly the ColorChecker image in my Blurb Standard paper book has absolutely no color shift when compared side-by-side with the actual ColorChecker PassPort "neutral" grayscale targets. I'm placing ProPhoto RGB images inside InDesign and converting to the Blurb.icc profile on export to PDF. Blurb suggests placing images soft proofed and converted using PS to CMYK with the Blurb.icc profile, and then export to PDF with NO conversion. I don't know what difference it should make, but I can confirm my method works quite well.

To better illustrate the "Paper White" numbers you posted I created a chart in Photoshop using those values and then below them a "neutral" 96 lightness area for comparison. PS only allows entry of Lab numbers without decimals, so I had to round the values. According to Adobe the human eye can only see a Lab value difference of 1, so these should still be very close to the actual paper color.

To my eyes the differences in paper white color are pretty small, but it's going to skew the soft proof. That's what I found when comparing the Blurb.icc soft proof in PS against the printed copy, "In fact they were actually slightly better than the PS soft proof view using the Blurb.icc profile." Any soft proof adjustments made using the one (1) Blurb.icc profile will most likely appear different in the final printed copy.

Special thanks to Andrew Rodney for doing the extra investigation and measurements!

Blurb Paper Options

(Click on image to see full-size)