6 Replies Latest reply on Jun 26, 2012 6:25 PM by rob day

    .png for print

    emmysue32 Level 1

      Hello Community,

       

      My team is considering moving to a .png workflow for print. The maximum print size is 12x12 inches. We receive and process photoshop & illustrator files, and are considering exporting as a hi-res .png as the print asset. Why would we do this? We print through an InDesign Processor, which creates pages on the fly, exports a pdf, and outputs to an Indigo printer. We have had issues with some of our files taking too long to render. We did a test, and .png flies through render, above and beyond any other filetype we tested.

      My question is: can anyone think of a good reason not to do this? We know it's rgb, we know it's a portable NETWORK graphic, and that it was never intended for this, but we also use InDesign Processors in a way no one else does, according to Adobe, and they can't solve this for us.

       

      I want to go into this experiment with as much clarity as I can, so I thought I'd ask all you smart peeps.

       

      Cheers,

       

      Emmy Williford

        • 1. Re: .png for print
          [Jongware] Most Valuable Participant

          The usual warnings you get from ol' grey-haired pros concerning PNGs are because People Are Dumb.

           

          Yes, with your precautions, workflow, and expertise with your own equipment and your own workflow, I'd say "go for it". Run a couple of jobs on a High Alert state -- do not experiment with a rush job, take your time to check every phase of input, processing, and output. I'm sure you'll find everything works just fine and dandy.

           

          ... "People Are Dumb", oh yeah. YOU sound like an experienced printer/document processor. Your average Dumb Person is going to half-read your question, not understand what the problem is, then half-read my answer. And then this DP is going to place a 72 dpi png he just copied from Google Images into his high quality offset printed glossy magazine, and then he's going to blame Adobe if it turns out to look like crap!

          • 2. Re: .png for print
            rob day Adobe Community Professional & MVP

            My question is: can anyone think of a good reason not to do this?

            Just make sure the rendering  improvement isn't because you're testing 8-bit pngs, which would likely create quailty problems down the road.

             

            PNGs can be saved uncompressed and with plenty of resolution, and can be converted to CMYK on export or print. So there shouldn't be a problem because you are controlling the res and compression—the images are not coming from the web where resolution and compression would be a problem.

             

            The only slight disadvantage is pngs can't have an embedded color profile when they are saved out of Photoshop. ID assigns the document's RGB profile to placed pngs. But that shouldn't be a problem because you can convert the incoming image files into one RGB editing space and assign that profile to your ID docs.

            • 3. Re: .png for print
              emmysue32 Level 1

              This is good news.

              Jongware, I promise not to do that! That's what gives pdfs and pngs a bad reputation.

              Rob, I checked and the pngs I tested are png-24 which I created by 'save for web & devices' in Illustrator and dialing in png-24 so it looks like the speed test is valid.

               

              You're right, color is my main concern. We don't actually assign a color profile to the assets, just a color mode, because a color profile gets applied at render (when the InDesign Processor creates the InDesign file and exports the pdf, it applies the cmyk print profile.) I'm thinking if we receive and process the original files in cmyk, then export in this rgb mode, and then it gets turned back into cmyk at render, at least no colors will be lost since it started cmyk. I still get uncomfortable with the interpolation of the colors, with all that back and forth. I can always tell when a file has been transferred between programs or color modes because the color values change, and our colors are dialed in to print well with the profile. We're going to send an assortment of assets through as ai and then as .png, and see how they look side by side but I'd love to hear if anyone has further tips on that color workflow I just proposed and how to lock down the colors as much as possible; I know pngs support swatches but they're rgb and our swatches are cmyk; would it be worth making sure they're cinched up in the png? (the rgb equivalent of the corresponding cmyk and no percentages or skewed values.)

              Thank you for the input, guys. I respect the input from forum peeps.

               

              Cheers,

              Emmy

              • 4. Re: .png for print
                rob day Adobe Community Professional & MVP

                the pngs I tested are png-24 which I created by 'save for web & devices' in Illustrator and dialing in png-24 so it looks like the speed test is valid.

                 

                So you're ok with rasterizing vector files? You would need a lot of resolution for files with fine lines, and you'll end up with 4-color blacks, which might be noticeable in black text.

                 

                We don't actually assign a color profile to the assets, just a color mode, because a color profile gets applied at render (when the InDesign Processor creates the InDesign file and exports the pdf, it applies the cmyk print profile.)

                 

                Your CMYK profile at export is the destination profile, but there also needs to be a source profile. So when you convert incoming files to RGB you are choosing an RGB space as the source (sRGB, AdobeRGB, ProPhotoRGB, etc.). When you place a PNG in ID the document's RGB profile is applied, so if you converted to sRGB in AI and your doc profile in ID is AdobeRGB, there'll be a color shift.

                 

                I'm thinking if we receive and process the original files in cmyk

                 

                There isn't much sense in requesting CMYK if you are converting everything to RGB—the source values will be long gone when you output, all you're doing is adding an extra color conversion.

                 

                 

                then export in this rgb mode, and then it gets turned back into cmyk at render, at least no colors will be lost since it started cmyk.

                 

                That isn't necessarily true, some CMYK colors are outside of the RGB gamut. Try filling a PS CMYK window with 100% cyan, then convert to sRGB and back to CMYK. Using US SWOP you'll get something like 69|15|0|0 

                • 5. Re: .png for print
                  emmysue32 Level 1

                  Hi Rob,

                   

                  How did you do that with the snippets of my text in your response?

                  I'm using your feedback in my research & testing, these are really good points. I'll get back with what we find. Just wanted to let you know.

                   

                  Cheers,

                  Emmy

                  • 6. Re: .png for print
                    rob day Adobe Community Professional & MVP

                    How did you do that with the snippets of my text in your response?

                     

                    Copy& paste the text you want to quote and click the quote button in the post editor.