Preparing your Print

[Guest]

Under image size in Photoshop I have an 8x10 file size that is 300 pixel/inch. I want to print this at a print shop bigger at 16x20.

Since 8x10 and 16x20 are the same aspect ratios can I leave it as is? Or should I rescale it by inches in Photoshop?

[davescm]

I would not rescale just resize it in Image > Image Size with resample unchecked. That will give you 20 x 16 inches at 150 ppi which will look fine at normal viewing distance. Doing it that way will not alter any image pixels or introduce any scaling artifacts.

Dave

[D Fosse]

Just print as is.

Upsampling is always a matter of minimizing the damage. It will never improve anything, it only disrupts the pixel structure. It will look better as it is.

You don't need 300 ppi at larger sizes, because it will be seen from farther away. 300 ppi is for books and magazines to be seen from less than arm's length. And even so, there's nothing special about the 300 number. It's just a theoretical upper limit based on a standard screen frequency of 150 lines per inch - the point at which it is not even theoretically possible to discern individual pixels. But that's not the same as sharpness.

A standard monitor is about 95 - 105 ppi screen resolution. Is it not sharp? Can you see pixels? Just for context.

EDIT: you had less typing, Dave 😉

[Conrad C · Accepted solution]

You can also ask the print shop if you should even bother.  They will (or should be able to) tell you which method works best for their equipment and workflow. Some of them say “Oh, send us the original unscaled, our print software does a better job of upscaling.”

[Guest]

Thank you for all the replies guys.