13 Replies Latest reply: May 1, 2009 9:08 AM by John Danek RSS

    Best to send files cmyk or rgb?

    emilycornfield Community Member

      I have created many product shots in Photoshop for a client's website. I saved all the original shots in high res as well as low res, all in rgb. My client has asked me to send some high res shots to some vendors who are them for print. What is the best format to send them in – rgb or or cmyk? Is it best to let the end user convert to cmyk when they go to print or should I do the converting beforehand? If i send them rgb does that allow the vendor to more easily apply their own profile, etc. or does it not matter? Thanks!

        • 1. Re: Best to send files cmyk or rgb?
          Rick McCleary Community Member

          When possible, always do the CMYK conversion yourself. If you have the proper information, and do the conversion correctly, it will save a lot of headaches and give you much more control.

           

          If you can discover what the final press conditions are for the images being printed, convert the RGB files to CMYK based on those press conditions. SImply ask your client. Or even better, engage in a little customer service and speak directly with the print provider. The question you want to ask is: "How do you want me to prepare the CMYK files for your press?" The range of answers the printer gives (depending upon how savvy they are) will include:

           

          1) "Just send us CMYK. We don't use profiles."

          2) "Use these Custom CMYK settings [xxx] to make the conversion."

          3) "Use our custom profile:[xxx] to make the conversion."

          4) "Use this canned profile:[xxx] to make the conversion."

           

          In the first two cases, you're dealing with a printer who is probably well-meaning, but very behind-the-times. In both of those cases, your best chance at success is to ask what kind of press it will run on (web or sheet-fed) and convert using either the GRACoL2006_Coated1v2.icc profile (for a #1 sheet on a sheet-fed press), or the SWOP2006_Coated3v2.icc profile (for a #3 sheet on a web press.)

           

          In the last two cases, follow their directions.

           

          The GRACoL/SWOP2006 profiles are available for download from the IDEAlliance website:

          http://www.idealliance.org/industry_resources/industrylibrary/icc_profiles_2006

           

          Oh, and one more thing:

          Fight mystery meat!!  (Files with no profile.)

          Be SURE to embed the profile into the CMYK file.

          • 2. Re: Best to send files cmyk or rgb?
            Ramón G Castañeda Community Member

            At the risk of making this reply sound like a copout, I have to say that you need to talk to the printing company to find out exactly what they want and to ask them for a specific profile to use for soft-proofing at your end.

             

            Sending RGB files has the advantage of having control but it requires confidence in the printer to know what they're doing.  But they may prefer CMYK, in whick case the target profile will be essential to you.

             

            You can also send them an RGB print right off your proofing printer and instruct them to "match this".

             

            EDIT:  Rick beat me to it.

            • 3. Re: Best to send files cmyk or rgb?
              emilycornfield Community Member

              Dear Rick,

               

              Thanks so much for your response.

               

              I get this request for files from my client so often that we decided 

              to upload a set of files to an ftp site so their vendors can access 

              them directly. Usually their vendors are using the files for an ad or 

              mail order catalog, and to get the info you suggested below would take 

              more time on my part than my client is willing to pay. Considering 

              this, would you suggest I make a generic cmyk version of everything? 

              If so, what settings would you recommend? The products are stainless 

              steel gift items (http://www.mkdistributors.com). While the general 

              color is important, exactness is not crucial.

               

              Thanks!

               

              Emily

               

              E.W.Kelly

              cornfield@lisco.com

              • 4. Re: Best to send files cmyk or rgb?
                Rick McCleary Community Member

                Hi Emily -

                 

                In the situation you describe (...not knowing the specific press conditions, and not being able to ask...) I'd do the following:

                Convert for a web press using either the USWebCoatedSWOPv2 profile that comes with Photoshop, or even better, download the set of profiles from IDEAlliance (listed in my post above) and use the SWOP2006_Coated3v2 profile.

                 

                Here's my thinking:

                You mention that your client uses these images in ads and mail-order catalogs. That means that, most likely, they are printed on a web press, so you convert for the average web press condition. USWebCoatedSWOPv2 has been the generally accepted web press standard for some time now, so you'd be very safe with that. The newer SWOP2006_Coated3v2 profile aims for the same press conditions, but uses a more realistic white point (not as yellow as SWOPv2), is much smoother in the shadows and, most importantly, is built based upon the new GRACoL/SWOP press standards that enlightened printers are adopting. I've had great success in the last year using that profile. Remember to embed the profile into the final CMYK file.

                 

                Make sure that when you're editing the files that you work on a well calibrated and profiled monitor, soft-proof using the CMYK profile and, if you have the capability (meaning that you have a well-profiled inkjet proofer), create a hard-proof/guide print to confirm your tonal/color adjustments.

                • 5. Re: Best to send files cmyk or rgb?
                  emilycornfield Community Member

                  Thanks so much Rick, this is very clear and helpful.

                   

                  Emily

                   

                   

                  E.W.Kelly

                  cornfield@lisco.com

                  • 6. Re: Best to send files cmyk or rgb?
                    Community Member

                    Always talk to the print provider before doing anything

                    • 7. Re: Best to send files cmyk or rgb?
                      Ramón G Castañeda Community Member

                      Emily,

                       

                      Just making sure that you are aware that by posting your email address in public like that you're exposing it to the automatic spambot harvesters of the web.  You must like having your inbox filled with spam.  

                      • 8. Re: Best to send files cmyk or rgb?
                        emilycornfield Community Member

                        oops, didn't realize that till I checked online.

                         

                        Nope, I don't need anymore spam that's for sure.

                         

                          Thanks I'll change my prefs right now.

                         

                        EMILY

                         

                         

                        Message was edited by: Host

                        • 9. Re: Best to send files cmyk or rgb?
                          emilycornfield Community Member

                          How do I change this pref?

                           

                          I can't find it within the forum, the prefs area doesn't seem to give 

                          me an option to "mask" my email, just to either get replies via email 

                          or not.

                           

                          Thanks

                          Emily

                          • 10. Re: Best to send files cmyk or rgb?
                            Rick McCleary Community Member

                            Hi Emily -

                             

                            Just like you, I'm learning my way around this new forum format after a long hiatus. Here's what I've discovered that will answer your question:

                             

                            In the bar near the top (under the "Forums" headline), click on "My Stuff > Profile".

                            Then, on the right side of the page, click on "Actions > Edit Profile"

                            On the resulting page, there's a radio button option to show/hide email address.

                             

                            HTH.

                            • 11. Re: Best to send files cmyk or rgb?
                              John Danek Community Member

                              Emily, what are your Color Settings in Photoshop?  Is your Rendering Intent > Perceptual?  What color space are your RGB's?  A big part of the conversion equation has not been discussed...the original RGB color space.  A 16-bit ProPhoto RGB is going to convert differently than an sRGB.  So, which one to use if you intend to go with the Gracol suggestion?  Unfortunately, most print vendors do not know the answer to that question.  And, if you supply them with the Gracol suggestion, will their RIP honor it?  Maybe Rick can answer that one.

                               

                              I agree, you should send CMYK's along with hardcopy proofs so everyone's on the same page ( so to speak ).  But, short of telling the print vendor " to match this "; supply a read-me file explaining your conversion process, settings, and intended profiles.  If, for some reason, your files fall outside of their workflow, they can target which part of your process ( if any ) needs to be modified ( if necessary ) in order to meet their RIP requirements. As suggested, best practice is to contact the print vendor early-on in the process and try to avoid automation.  Each vendor is different, each Direct-To-Plate RIP is different, as is every monitor.  So, I would not recommend building a database full of CMYK files which may or may not be sufficient for every print vendor.  Yes, it can be done, but the final output device ( press ) is going to determine which CMYK files is most appropriate and that includes a certain RGB space before conversion.

                               

                              Rick, does Gracol explain what the differences between the 3 .icc profiles in their download are?  If so, where?  I'd like to take a closer look at these to determine which one is most appropriate for what press.

                              • 12. Re: Best to send files cmyk or rgb?
                                Rick McCleary Community Member

                                John -

                                 

                                Your 2 questions directed at me:

                                 

                                1) GRACoL - will the printer's RIP honor it?

                                The printer's RIP will either honor or ignore an embedded profile - doesn't matter if it's a GRACoL, the old SWOP, or Aunt Minnie's profile. As long as it's an ICC profile, it will be treated the same as all other ICC profiles. Once we send a file downstream, we have very little control (read: none) over what happens to it. Our only option is to exercise best practices at each step of the way.

                                 

                                BTW, there are many large web printers that will reseparate the files using an ink-optimizing software (like Alwan.) Without an embedded profile, they have no idea what colors the CMYK numbers are supposed to represent.

                                 

                                2) 3 GRACoL profiles: what's what?

                                The documentation on the IDEAlliance site is not very well organized. You have to dig to find answers (but they're there.)

                                In short the three profiles are built for the following press conditions:

                                 

                                GRACoL2006_Coated1v2

                                #1 coated sheet, sheet-fed press, 320% total ink

                                 

                                SWOP2006_Coated3v2

                                #3 coated sheet, web press, 300% total ink

                                 

                                SWOP2006_Coated5v2

                                #5 coated sheet, web press, 300% total ink

                                 

                                I use the SWOP2006_Coated3v2 profile now all the time as a replacement for the old USWebCoatedSWOPv2 profile. Better all around.

                                I use the GRACoL2006_Coated1v2 for sheetfed jobs on a #1 sheet when the printer has no profile to offer. Also excellent.

                                 

                                EDIT: We're going to be doing some real-world on-press tests with these profiles this fall and will be publishing the results when we're finished.

                                • 13. Re: Best to send files cmyk or rgb?
                                  John Danek Community Member

                                  Rick, thank you for your answers.  I did register with IdeaAlliance and downloaded some helpful information.  Your .icc profile descriptions help alot.  Going a bit off topic here and sorry for that.