8 Replies Latest reply on Oct 1, 2012 5:55 PM by ChristianAaltonen

    Enlarging images for offset printing

    ChristianAaltonen Level 1

      Hi guys,

       

      some images I have to include to the project has insuficient size {sometimes less than half {125 DPI instead of 300}. What's your opinion when considering the best way to enlarge them. Should I just place them to ID and without any pardons export the final PDF or is better to enlarge each one manually? I am just curious to hear your experiences.

       

      Thank you

        • 1. Re: Enlarging images for offset printing
          MW Design Level 4

          The DPI doesn't matter much. What does matter is the pixel dimensions. Resizing upwards in ID will make the images fuzzy. More fuzzy the larger you increase their on-page size.

           

          So if the images are being sized downwards after placing them, the effective DPI increases. Sized larger and the effective DPI is decreased.

           

          If it at all matters, there are two reasonable options. One costs, does a little better job: a plug-in for Photoshop. The other is free: Smilla Image Enlarger. Smilla will do a pretty decent job as long as you are beginning with a quality image and are not unduly sizing upwards.

           

          Either way, you would do so on each image. That is unless you are beginning with images that can be resized exacly the same amount without changing the WxH ratio. Then Smilla can process a queue.

           

          Take care, Mike

          1 person found this helpful
          • 2. Re: Enlarging images for offset printing
            winterm Level 4

            how are you going to enlarge it? upscale in photoshop? than it depends... if it's background picture with soft colors, not detailed, you can get still satisfactory result. If it is human face, or product image, or any other "front" detailed image, you should get version with better resolution. Or, at least, warn your client about the problem and share responsibility

            • 3. Re: Enlarging images for offset printing
              ChristianAaltonen Level 1

              MikeWenzloff wrote:

               

              The DPI doesn't matter much. What does matter is the pixel dimensions. Resizing upwards in ID will make the images fuzzy. More fuzzy the larger you increase their on-page size.

               

              So if the images are being sized downwards after placing them, the effective DPI increases. Sized larger and the effective DPI is decreased.

               

              If it at all matters, there are two reasonable options. One costs, does a little better job: a plug-in for Photoshop. The other is free: Smilla Image Enlarger. Smilla will do a pretty decent job as long as you are beginning with a quality image and are not unduly sizing upwards.

               

              Either way, you would do so on each image. That is unless you are beginning with images that can be resized exacly the same amount without changing the WxH ratio. Then Smilla can process a queue.

               

              Take care, Mike

              Thank you Mike,

               

              sorry, I was not clear enough — I was talking about Effective DPI. Thank you for your time!..

              • 4. Re: Enlarging images for offset printing
                ChristianAaltonen Level 1

                Well, there are some faces, but I can not do anything else than just enlarge it. I am curious to compare a pure Ps result with some of the plugins. Thank you for your response mate.

                • 5. Re: Enlarging images for offset printing
                  Peter Spier Most Valuable Participant (Moderator)

                  In addition to the type and quality of the image, the paper you use will make a difference in what you can get away with. 125 ppi is probably adequate for newsprint, for example, in a pinch, and will look better on an uncoated stock than it will on gloss.

                  • 6. Re: Enlarging images for offset printing
                    rob day Adobe Community Professional & MVP

                    Upsampling doesn't add any meaningful information to an image and can often make things worse. The top image is 10ppi, the bottom is the top image upsampled to 300ppi:

                     

                    Screen shot 2012-09-11 at 6.45.51 PM.png

                    • 7. Re: Enlarging images for offset printing
                      winterm Level 4

                      Rob Day wrote:

                       

                      Upsampling doesn't add any meaningful information to an image and can often make things worse.

                       

                      Absolutely correct... and your example is the WORST case for upsampling . Sure, one must use upsampling with very big caution, and even better - never...

                      Sometimes it happens in the real world - you're forced to use (say, client insists) natively low-contrast, a bit blurry background with a very low res. My printer guys ignore (I know) resolutions of 125 and up, but if they get 96 or even 72... chances are they become nervous and may call me in the middle of the night...

                      I'd better upsample it to a 'printer-guys-stay-silent' level and sleep tight... if it's not something like your pattern, of course .

                      • 8. Re: Enlarging images for offset printing
                        ChristianAaltonen Level 1

                        Well, you are absolutely right. But in this case the custommer is who rules. Thank you for your time guys!