PDF in CMYK color space?

Is it possible to create a CMYK PDF with ColorSync filters? I have tried using the "Generate PDF-X/3" filter, with "Generic CMYK" as the target profile and transparency flattening, but the printer still says that my PDF is in the RGB color space ... What about if I first convert images to the CMYK color space before importing them to Pages?

OK, here we go.

You do not have to hard convert to CMYK. You can keep your photograph in RGB with the source ICC type MNTR monitor or type SCNR scanner profile embedded inside the photograph.

You do have to include the ICC profile for the intended printing condition, that is, the OutputIntent that specifies the ink limit, gray balance, shadow drawing, hightlight drawing, and more.

The Generic CMYK Profile is a poor man's printing condition. It is a small colour space for the gray paper used in US printing of periodicals (SWOP).

Pick yourself a printing condition with a larger color space, and in particular a colour space that suits what you are actually going to print. ISO 12647 profiles are at www.eci.org.

PDF/X1a mandates only four channel CMYK, no three channel RGB or LAB. PDF/X-3 permits CMYK with embedded source ICC type PRTR profile, but prefers RGB or LAB.

Why would you want to embed the ICC type PRTR printer profile for the four component CMYK, if you choose to convert manually before placing in any PDF/X-3 process?

Because if you don't embed the source colour specification, all you have is the colourant shaping with no concept of the colours those shapings should form. Thus, you cannot contract proof.

The thing to keep in mind is that ICC type PRTR printer and ICC type MNTR monitor profiles are by definition bidirectional, that is, they support a transform from device space into the colour connection space and from the colour connection space into device space. This is why they can serve both as source and destination in a colour matching session, and this is why they can serve as well in Photoshop as 'working spaces' as in PDF/X-3 as OutputIntents. In other words, if you are not imaging to a digital press or an offset press using a four component CMYK printing condition for a reflective substrate, you can just as happily image to a four component RGB printing condition in a film recorder for a transmissive substrate. And you can do that from Aperture and Pages through ColorSync.

/hh

Henrik -- Can you offer this fellow any advice?

http://discussions.apple.com/thread.jspa?threadID=1780020&tstart=0

I too am trying to convert a document into a pdf for printing that requires CMYK end production and seperated black text.

I cant find an answer anywhere and sorry but the hh post below is extremely complicated for ordinary people to comprehend let alone apply

Regards

Paul

Can you offer this fellow any advice?

Done, he needs to be directed to the ColorSync community list. That list is deep into display configuration and display characterisation. /hh

Is there a way to produce a PDF in the CMYK color space with ColorSync Utility?

If you are in the US, then your printer probably does not want PDF/X-3 in the first place. Your printer probably wants PDF/X-1a which is why you are being asked to provide a print master that is preseparated. He wants you to take responsibility for the product he wants to sell you, and which he does not want to declare the specifications for by supplying you with an ICC profile for his printing condition. You should supply three channel RGB/Lab, he should supply his profile for his printing condition, your get to preview and proof what he is offering to sell you, and you send him what you have accepted. If he does not deliver, then you don't pay. Period.

'CMYK' does not define colour, it simply defines four colourant channels in a data file. For the colour community I created a graphic that showed what colours the selfsame CMYK colourants reproduce in a set of common printing conditions, from inkjet presentation printing to offset on high grade art paper to offset on low grade periodicals paper. You can manually convert into 'CMYK' in your scanner software, your camera software, or your colour correction software (Apple Aperture, Adobe Lightroom, Adobe Photoshop), but to do so you must know what printing condition to convert into. Then you can embed the ICC profile you picked into that 'CMYK' and save the colourants and the profile together into TIFF or PDF. Then you can place that TIFF or PDF into an Apple application such as Pages. And then you can produce a PDF/X-3 printing master, but for that printing master you must have an ICC printer profile as OutputIntent.

If the ICC printer profile you selected to manually convert into 'CMYK' before saving your TIFF or PDF to disk is different from the ICC printer profile you selected as your OutputIntent in the PDF/X-3 filter, then your manually converted 'CMYK' will be automatically reconverted to the OutputIntent profile, which produces a double conversion. In other words, it makes no sense to manually convert into 'CMYK' other than to purchase printing from an unprofessional printer who does not want to be held to providing you with any particulars. You have no idea of the lightness and tint of the paper, and so on and so forth.

So, if you want to produce a 'CMYK' printing master, then you must produce one by manually converting your images (e.g. in Adobe Photoshop) and illustrations (e.g. in Adobe Illustrator) into an ICC printer profile (Adobe calls this your 'CMYK Working Space'), then save your images and illustrations to disk as TIFF and PDF with the 'CMYK Working Space' embedded, then place your images and illustrations into Pages, and then pick the selfsame ICC printer profile as OutputIntent in the PDF/X-3 filter. This way you will not get a double conversion, although if your printer is as utterly unprofessional as it seems you will have no idea of what he produces anyway.

/hh

Henrik,

Is it not possible to simply offer a simple step by step answer to the posters as we do for just about everything else here?

Is it not possible to simply offer a simple step by step answer

You mean, like, a simple step by step answer to avoiding double 'CMYK' conversions in producing a PDF/X-3 printing master, and what one needs to know in order to avoid this in configuring colour capture (Aperture, Lightroom) and colour correction (Photoshop) software to support a tagged CMYK process? I just did.

But if a person has no foundation, then there is no such thing as a 'simple step by step answer', because that person does not know what questions are meaningful and what questions are meaningless. Read a book to begin with, it helps when one is a beginner. Read Bruce Fraser, for instance. Or read Matthias Nyman's four colourants and one photograph, which won the Benjamin Franklin award for popular science writing.

/hh

Then give your advice in 2 parts.

One what should you should do if you are an amateur without either the technical skills or necessary hardware.

ie do nothing, avoid it, give it to the printer to work out etc.

Explain the possible consequences of your actions, dire or otherwise.

Two what you can do if you are a professional and have the necessary technical skills and hardware and what they need to be to do the job.

We have already been down the path of one "solution", that of editing filters in the ColorSync Utility to ultimately get no result, so lets not send more posters on wild goose chases.

I cant find an answer anywhere and sorry but the hh post below is extremely complicated for ordinary people

The fact is that when you step into PDF/X-3, you step into professional print publishing. If you step into Final Cut Studio, you step into professional video publishing. If you step into Logic Pro, you step into professional sound publishing.

If you expect to understand Final Cut Studio because you watch television, you are probably not on the proper path to working with Final Cut Studio. Similarly, if you expect to understand professional print publishing because you print on an inkjet, you are also on the path to problems.

Since the introduction of the Apple LaserWriter in 1985, responsibility for producing the printing master has been pushed back from the print shop to the prepress shop and from the prepress shop to the typographer's and photographer's studio.

PDF/X-3 is there to try to help in this process, but if you can't be troubled with the technicalities, then perhaps you should consider a colour consultant. Something should be done, and something is being done, but it takes time.

1. Obtain the ICC profile from the printer for his output device.

Correct. Either the shop printing condition or an ISO 12647 printing condition to which the shop can configure and calibrate the printing condition it is selling you. If the latter, you can get default ICC printer profiles for standard printing conditions at www.eci.org.

2. Create a filter in ColorSync Utility for generating PDF/X-3 documents with the ICC profile as the output intent (besides flattening the transparency and applying an appropriate resolution).

Correct.

3. Print to PDF in Pages.

Incorrect.

Your PDF/X-3 filter will become available in the system dialog for File > Print > Save as PDF. In saving as PDF you pick your PDF/X-3 filter as the template for the save process.

4. Use ColorSync Utility to modify the resulting PDF with the filter I created in ColorSync Utility.

(or 3-4. Print directly to PDF through the filter from Pages)

Your second step to combine 3 and 4 is correct, your first step 4 to save to disk and then postprocess in the ColorSync utility is incorrect.

5. Send this PDF/X-3 to the printer.

Correct.

It seems that no hard conversion from RGB to CMYK should be necessary if I take these steps, is that correct?

Correct.

If I send the printer a PDF in the RGB color space, should it cause problems for him to convert the PDF himself to the color space of his output device?

No.

You create three channel RGB images in the RGB colourant data model (it's just a model, it is not a colour space which a size and a shape of the gamut).

You save your colourants to disk in TIFF or PDF format with the ICC profile for the capture colour space (e.g. the ICC profile for your specific scanner with a Kodak EktaChrome IT8) or correction colour space (e.g. Joseph Holmes' RGB working space for EktaChrome). This ICC profile is the _colour space_ that you can view in the ColorSync Utility as a specific size and shape of gamut. The colour space determines what colours the colourants in your TIFF or PDF image should reproduce on different colour devices.

You now have a pagination with photographic objects in three component RGB, and you know what colours those colourants are supposed to reproduce. You then include the production profile for the printing condition. Your source profiles must match to this destination profile in the matching session, so all your photographs get converted to the SAME ink limit, the SAME graybalance and so forth. This unifies the inking behaviour and the colour formation for your printing.

If you imagine that in your pagination you place photographs which are manually converted into four component CMYK using a different ink limit, a different graybalance and so forth then you have not unified your inking behavour and colour formation for the printing process. This is IDIOTIC because the only way to correct in this case is to change the calibration of the individual inking zones on the offset press - increasing or decreasing the cyan, magenta, yellow or black for that zone.

It used to be that lithography on the press was the only way to work. This was in the days of EPS and EPS DCS, and before that in the days of photographic printing masters pasted together manually piece by piece to make the printing planes. Nobody in their right mind works that way today.

/hh

Then give your advice in 2 parts.

Oh Lord, does it have to be so difficult to take the time to think. I can give guidelines, but I can't configure people's displays and printers and presses nor their colour capture and colour correction applications nor indeed their printer drivers. The idea is that the person who controls a colour device is responsible for configuring, calibrating and characterising that colour device, and for supplying co-workers and customers with the ICC profile for that colour device in order that they in turn can see what colours that colour device is capable of forming, and what colourants that will be computed in order to form those colours on that colour device. In other words, you are supposed to understand your colour devices as well as the open standards framework for managing the colour information passing through the framework. This is not simple, but it is a whole lot better than having a couple of companies decide that, sorry mate, but there is one size gamut for any colour device, or indeed having as many colour management systems as there are suppliers of hardware and software. Which was how it used to be, and there is no way the community is going back to that nightmare. /hh

So your recommendation is to be an expert, so that you can understand the advice?

Why need to ask then?

Henrik Holmegaard wrote:

Then give your advice in 2 parts.

Oh Lord, does it have to be so difficult to take the time to think.

Yes, the reason many of us use a Macintosh instead of XWindows is that we do not want to think. We want it to just work. We do not buy computers to learn about computers but to have certain tasks solved by the computer. We want the computer to work for us - not us for the computer.

On one hand, sometimes one gets a much better result if one takes the time to think and understand.

On the other, simple instructions that take as little time as possible to understand are what most of us aim for.