I shoot RAW and am printing a book using Adobe Indesign. The printer will get a print ready pdf, but should I save the images to Indesign as hi-res JPEGs or TIFF files for the best print outcome? I use Lightroom to edit my images so either is easy. So confusing... as there are sooooo many articles and they all have a different take on this matter.

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Your print service should know the best settings to use. Consider contacting them for guidance. If they do not specify anything beyond using 300dpi, you should just export the PDF with images at 300dpi with high-quality JPEG compression.

  • Get proof copies to check that output meets your quality standards.

  • Increasing image resolution is unlikely to improve print output.

    • For computer screens, what is called dpi should really be ppi (pixels per inch) because each "dot" contains full color information.

    • For printers, dots contain only one color and intensity. It takes many dots to represent different colors and intensities, so a much higher printer dpi is needed to represent a lower screen dpi (ppi).

  • Lossless compression is unlikely to improve print output.

    • The difference between high-quality JPEG compression and lossless compression is insignificant as long as there will be no further post processing.

    • Depending on how many images are in your document, using high-resolution, losslessly compressed images may make the file unusable by overloading printer memory. (Ever tried using a multi-gigabyte PDF file?)

Regarding file and compression formats:

  • TIFF is an image container format. Images may be compressed within TIFF files using any of a number of compression algorithms, including JPEG.

  • PDF also supports several image compression algorithms, including JPEG and JPEG2000.

  • There is a good chance the PDF will be "optimized" by the print service so that images are compressed with JPEG.

Optimizing Images

Trying to optimize files by hand is unlikely to produce significantly better results than what software can do automatically. It can also lead to complications if settings need to be changed mid-way through the project.

You should use your usual workflow and colorspaces to output images at max resolution so that all images are consistent. Then import the full-resolution images into your layout software.

When ready to output, let the export tool resize and convert colorspaces for you. This will require the least effort and provide the greatest flexibility, if any settings need to be changed later.

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  • Thank you. It is a photography book so it will have many images but as mentioned, Indesign converts the file into a print ready pdf for the printer to use. I'm unsure how that all works in the scheme of things. But I am worried that the image quality may be lost... The printer just wants images to be 300dpi, they aren't worried about anything else. – Iri Feb 4 '19 at 5:35
  • Would using the exact size I'll be using in the book help with the quality? I can adjust it all when saving from RAW across to jpeg in Lightroom? – Iri Feb 4 '19 at 8:29
  • If using offset printing, optimizing each image for the correct resolution can have a significant impact. – Michael C Feb 4 '19 at 16:39

Having dealt a lot with print services, I'd say the printer's preferences are the key. I am (always) a bit surprised when printers say nothing matters in terms of color or, as your question pertains, file format. I have used printers who prefer the files in pdf or in tiff, and also those wanting jpegs (although less often).

Basically, the more the printer converts, the more likely you may end up with something looking different from what you intended (and how the images looked when you printed them at home or at another printer.) My comments below are based on experience, but may not involve using the right technical terms (apologies!).

I would recommend digging a bit deeper with staff at your printing shop, if they have the patience for this type of questions. At the very least, you need to know if they are printing cymk or rgb, so you can prepare the files with the right color format.

A second question is to ask if the color space is sRGB or AdobeRGB.

And then the third is file format.

Can you get paper samples? Is the paper coated or not? Can you get the printer profile they use?

My experience is, the output from printers who don't give that info, can be hit or miss. And misses can be expensive disappointments....

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Personally, I would avoid any lossy compression in high-quality printing files. That said, the effect of minimal JPEG compression might be invisible depending on print method, paper stock, screen frequency, and other factors. For newspapers, JPEG image compression is commonly used.

TIFF is a "standard" format that can vary in different software. It was always meant to be an extensible standard ("tagged" image file format; the tags are ways of identifying features in the file). TIFF is generally considered to be lossless, but it doesn't have to be.

By the way, image resolution should be tied to screen frequency, paper stock, press type, etc. There is no one resolution fits all.

"300 dpi" is not an image resolution. Images have pixels, not dots, so image resolution is "pixels per {something}" (ppi for pixels per inch). Many people confuse the two, but there's a difference.

Offset printing requires halftone screening to print images. Printing presses can only print solid dots. Halftoning converts image values into different sized dots. A very general recommendation is to have image resolution of twice the screen frequency. So, 300 ppi images for 150 LPI halftone frequency. Having more than 2x image resolution can actually result in lower print quality. It has to do with halftoning again, which is a fascinating subject in itself. See any Adobe print production guide. I highly recommend "Makeready" by Dan Margulis for all things about color and print production.

By the way, be aware that the conversion to PDF files can introduce compression and downsampling. I would set the PDF output settings to no downsampling and no compression if the images in the In Design layout have been prepared correctly.

You do know that almost all images to be offset printed need to be color-corrected, right? Also, unsharp masking is often used before printing. I would try to talk to a color expert at the print shop. And, perhaps most important, what proofing method will be used? If you are printing books, you want to make sure to approve a proof of every page before the press run.

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    The reason many people conflate ppi with dpi is because the EXIF standard does it. Where EXIF info should label "ppi" as "ppi", it instead labels it as "dpi". – Michael C Feb 4 '19 at 16:35
  • Good point @michael-c. – user8356 Feb 4 '19 at 18:52
  • Exif, and also the TIFF specification says dpi, and the JPG specification says dpi. There are of course no ink drops in image files. Scanners say dpi (Epson and Canon scanners spec optical resolution and hardware resolution in dpi, meaning obviously pixels of course) and there are no ink drops in scanners. These spec writers are the experts that know things. It may have been jargon, but it is Not a confusion, dpi has always been the name of image resolution. A colored dot is the definition of a pixel. – WayneF Feb 5 '19 at 2:16
  • They might be experts but have not updated the terms. It IS a confusion. DPI should be updated if they mean PPI. Regardless of who is the "Expert". No... A Pixel is NOT a colored dot. Pluto was a planet until people actually decided to update the definitions. This site is also made for experts at some degree. It is a reference point... Start here. – Rafael Feb 5 '19 at 19:55
  • Curious, just who is it that says it needs to change? It's been dpi for so long, and it always worked before. I don't mind if anyone prefers to call it ppi (altho I learned it as dpi), but we ALL absolutely must understand it either way, because most references of course say dpi (is the name of it). Google the phrase (with quotes) of "72 dpi" and "72 ppi". 78.7 million vs 0.189 million, and we know 72 dpi NEVER refers to ink drops. :) I get bothered by the self-righteous shouting to Novices that dpi is WRONG, when that is of course what they see everywhere. That's no help to anyone learning. – WayneF Feb 5 '19 at 22:33

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