21 Replies Latest reply on Oct 7, 2015 1:15 PM by evans62778818

    InDesign generated 'Press Ready' PDF files

    CraigAustralia

      I have always prepared images (300dpi resize & CMYK conversion) in Photoshop and imported them into Indesign.  Is this even necessary now? Does a 'Press Ready' PDF generated from InDesign do all of this? I understand that if an image is low res to start with then it's never going to be good - but if the image is high res (say 5000px x 3500px) and imported into a 5cm x 10cm image box - and only displaying at say 7% size will the PDF export have a 300dpi file at 1:1 final print size. I'd actually like to keep all images in RGB for all purpose use and avoid doubling up on disc space.

        • 1. Re: InDesign generated 'Press Ready' PDF files
          Steve Werner Adobe Community Professional & MVP

          You best bet are to use the PDF presets within InDesign (File > Export > Adobe PDF (Print)). For commercial printing, the best choices are PDF/X-4 or PDF/X-1a. Check the settings for each one of these and check with your printer which works best for their workflow.

          • 2. Re: InDesign generated 'Press Ready' PDF files
            CraigAustralia Level 1

            Steve, I'm already Exporting from InDesign using the 'Press Ready' setting. I don't think you understood my question. Thank you.

            • 3. Re: InDesign generated 'Press Ready' PDF files
              CraigAustralia Level 1

              Let's say - prior to importing - all the images were sharp, had good colour and were high res. Do I even need Photoshop in the equation? Will a 'Press Ready' PDF exported from InDesign provide a true press ready file - and top quality outcome (print).

              • 4. Re: InDesign generated 'Press Ready' PDF files
                Steve Werner Adobe Community Professional & MVP

                There's no Press Ready setting. See below. Do you mean Press Quality?

                 

                InDesign017.jpg

                Generally, PDF/X options (PDF/X-1a and X-4) are better because they're specifically follow a ISO standard for print exchange. For example, certain color spaces are allowed. Fonts must be embedded. Page geometry and trapping must be defined in the file. The Press Quality setting doesn't support that standard.

                 

                But you need to check with the printer to see which works best for them.

                • 5. Re: InDesign generated 'Press Ready' PDF files
                  CraigAustralia Level 1

                  Sorry, I meant [Press Quality] not 'Press Ready'. Do you get what I mean about "not needing photoshop"?

                  • 6. Re: InDesign generated 'Press Ready' PDF files
                    Dov Isaacs Adobe Employee

                    (1)     Once your images are ready for placement into InDesign, you don't have further need for Photoshop in the workflow.

                     

                    (2)     There is absolutely no need to resize images to 300dpi in Photoshop prior to placing into InDesign. If the original images are of higher resolution, InDesign can downsample them as part of the PDF export process. If the original images are of lower resolution than 300dpi, it buys you absolutely nothing in terms of quality of resampling to a higher resolution – this adds absolutely no quality to your imagery. The RIP will properly upsample if necessary to exactly the resolution required by the device.

                     

                    (3)     Likewise, there is absolutely no need to convert your RGB images to CMYK in Photoshop. The recommended workflow is to keep the images in RGB with ICC profile when placing into InDesign. InDesign can do a proper RGB to CMYK conversion when printing or performing PDF export, but even for PDF export, we recommend that RGB to CMYK conversion occur at the RIP where the exact CMYK printing conditions are known.

                     

                    (4)     Adobe recommends use of the PDF/X-4 PDF export settings without any modifications that would convert RGB to CMYK. All modern PDF RIPs can easily and properly handle both live transparency and ICC color management, converting ICC profile-tagged RGB artwork to the final CMYK color space.

                     

                              - Dov

                    • 7. Re: InDesign generated 'Press Ready' PDF files
                      Eugene Tyson Adobe Community Professional & MVP

                      Dov on "Point (2)"

                       

                      There would be a need to resize images to 300 ppi at 100% for placement in InDesign as resizing images would require a Sharpening before placing.

                       

                      This would only be useful for images that are of very high quality that needs a good reproduction.

                       

                       

                      But generally - for the last 10 years I haven't used photoshop to resize images and place them at 100%.

                       

                      The last time I did that was for an Artbook.

                       

                       

                      But I'd say for a lot of use there's generally no need to go near Photoshop - unless the photographs are specifically requested to be reproduced as best as possible.

                      • 8. Re: InDesign generated 'Press Ready' PDF files
                        Eugene Tyson Adobe Community Professional & MVP

                        Eugene Tyson wrote:

                         

                        There would be a need to resize images to 300 ppi at 100% for placement in InDesign as resizing images would require a Sharpening before placing.

                         

                         

                        Just to qualify that

                         

                        *as InDesign export to PDF doesn't perform a sharpening when it downsamples images for export.

                        • 9. Re: InDesign generated 'Press Ready' PDF files
                          BBP

                          We prepare press pdf files on a regular basis.

                          With regards to images you have to be aware that distiller will not upsample images if they are below 300dpi. Also if an image is sized within InDesign above 100%, then the image will be downsampled accordingly in the final press pdf.

                          If an image is below 300dpi and the quality is suspect, although not perfect a package such as Perfect Photo Suite has an interpolation feature within it where it will try to intelligently increase the resolution and add sharpening etc.

                          It is always wise to try to have all imagery as close to at least 300dpi as much as possible as all modern pre press software RIPs will flag up lower res images in it's flightchecking procedures.

                          I've included a screenshot of the settings we use here with regards to image processing in Acrobat Distiller.

                          Hope this helps.

                          Screen Shot 2013-11-18 at 10.48.06.png

                          • 10. Re: InDesign generated 'Press Ready' PDF files
                            Eugene Tyson Adobe Community Professional & MVP

                            If a prepress department is flagging images below 300 ppi as a problem then they don't know what they're doing, they're just following procedures that are archaic and non-sensical.

                             

                            Your DPI is completely dependent on the LPI of the rip and whatever the LPI is is multiplied by 1.5 to get the DPI of the image.

                             

                            150 LPI rip then 225 PPI is fine.

                             

                            175 LPI rip then 262.5 PPI is fine

                             

                             

                            Some rips might be running at 200LPI and if so then 300 PPI is preferred.

                             

                             

                            But flagging every image of below 300 PPI as unusuable in print is way OTT.

                             

                            It also will depend on the content of the image. If the image is of things without much detail you could go as low as 200 PPI or 150 PPI and never see any difference in print.

                             

                            If it's sharp objects and details then you might need to go as close to the optimum PPI depending on the RIP LPI.

                             

                            Where 300 would be overkill for a 150LPI rip and could actually lose detail rather than enhance it.

                             

                            Where a 225 PPI image on a 150LPI rip could give better quality than a 300 PPI image.

                            • 11. Re: InDesign generated 'Press Ready' PDF files
                              BBP Level 1

                              I wasn't saying that an image below 300dpi is unusable, I was just stating that all modern rips use an industry standard flightchecking procedure.

                              Whatever you say 300dpi is an industry standard resolution for platemaking and I was hoping in my post to help the person concerned with regards to image placement within InDesign and outlining what would happen if an image, even if it's a CMYK 300dpi image will deteriorate in quality according to it's enlargement if it's sized above 100%.

                              Probably best that I don't respond anymore to these forums.

                              • 12. Re: InDesign generated 'Press Ready' PDF files
                                Eugene Tyson Adobe Community Professional & MVP

                                Why do you feel you can't respond on the forums?

                                 

                                You stated that 300 PPI is a preflight check that people make. You never clarified that 300 ppi is not reflective of how an image should be prepared.

                                 

                                I have heard the 300 PPI image myth for too long.

                                 

                                These forums are found by searches on the internet too - it's always best to try and qualify them accuartely so later parties and the current OP can get the best information.

                                 

                                 

                                Even if it is 300 DPI an they scale it to 125% it will be fine on a 150 LPI rip. As it would be 240 PPI.

                                • 13. Re: InDesign generated 'Press Ready' PDF files
                                  Eugene Tyson Adobe Community Professional & MVP

                                  And just to say - most of your information was spot on.

                                   

                                  You said a lot of things that I agree with.

                                   

                                  But I hate seeing that 300PPI as a standard for images going to press - it simply isn't true.

                                   

                                  I know it's part of a preflight check - but it shouldn't be.

                                   

                                  Is it a good rule of thumb? In most cases Yes.

                                   

                                  But in some cases where you need to get a larger size and you don't have a higher quality image - then you can break that rule of thumb and sleep easy.

                                   

                                  But the best thing to do is talk to the prepress and ask them what LPI they are using and the minimum PPI they can print on that LPI.

                                  • 14. Re: InDesign generated 'Press Ready' PDF files
                                    rob day Adobe Community Professional & MVP

                                    Whatever you say 300dpi is an industry standard resolution for platemaking

                                     

                                    The problems with getting caught up with 300ppi as a magic number can go both ways.

                                     

                                    This image which is a combination of line art and color would benefit from more than 300ppi (if you care about the 6pt. captions and fine keyline):

                                     

                                    Screen Shot 2013-11-18 at 10.23.49 AM.png

                                     

                                    This image has no details or high contrast edges that would need 300ppi to resolve:

                                     

                                    Screen Shot 2013-11-18 at 10.25.39 AM.png

                                     

                                     

                                    300 is a useful catchall but doesn't guarantee anything.

                                    • 15. Re: InDesign generated 'Press Ready' PDF files
                                      Dov Isaacs Adobe Employee

                                      @BBP,

                                       

                                      Simply stated, you should not be using distillation of PostScript to produce PDF from InDesign. This is an archaic practice that does not generate particularly good PDF. The PostScript generated by InDesign is optimized for direct printing to a PostScript device and is not optimized for PDF creation. You lose all color management and live transparency. That may be great for 1990s PostScript-based print workflows, but not for modern day PDF-based workflows.

                                       

                                      For PDF export, Adobe most strongly recommends PDF/X-4 settings for both traditional offset / gravure / flexo printing as well as digital printing.

                                       

                                      In terms of RIPs, the RIPs themselves don't flag images in terms of resolution. Any such flagging is typically done by separate preflight software, often improperly setup to reject content for fairly arbitrary reasons. In the case of image resolution, what do you do with a screen shot that you need to reproduce. These are often only 72 to 96dpi! Generally speaking, the best approach is to simply leave them as-is and let the RIP do the intelligent interpolation. Artificially upsampling and then resampling at the RIP (all images, regardless of resolution, are resampled at the RIP for halftoning and separation purposes) can actually cause unwanted artifacts that would not show if the original image was not  mucked with to try to improve it.

                                       

                                                - Dov

                                      • 16. Re: InDesign generated 'Press Ready' PDF files
                                        CraigAustralia Level 1

                                        Thanks very much to everyone for thier feedback. The next file that goes to the printers will be a PDF/X-4.
                                        Talk to you all again - and if something hits the fan. Cheers.

                                        • 17. Re: InDesign generated 'Press Ready' PDF files
                                          Dov Isaacs Adobe Employee

                                          One last quick note …

                                           

                                          PLEASE, before you send a PDF/X-4 to your printer, make sure that they confirm that they even know what that PDF standard is and they are willing and capable of accommodating it. Their workflow may actually support PDF/X-4, but they may not even be aware of it.

                                           

                                                    - Dov

                                          • 18. Re: InDesign generated 'Press Ready' PDF files
                                            CraigAustralia Level 1

                                            Thanks Mate - will do.

                                            • 19. Re: InDesign generated 'Press Ready' PDF files
                                              CraigAustralia Level 1

                                              One last thing - is it ok to use native Photoshop format images (with layers) in InDesign?

                                              • 20. Re: InDesign generated 'Press Ready' PDF files
                                                Eugene Tyson Adobe Community Professional & MVP

                                                Absolutely - tiff and psd are recommended for bitmap files.

                                                 

                                                If your Photoshop file has text layers, vector masks, or vector shapes - then PDF is preferred.

                                                 

                                                 

                                                If you have smart objects they will be rasterised to the document image settings on output/save.

                                                • 21. Re: InDesign generated 'Press Ready' PDF files
                                                  evans62778818

                                                  Best answer to OPs question.