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.