What resolution should my pictures have?Updated 2 months ago

An average photo camera currently has at least 20 megapixels. This value describes the number of pixels that make up a photo. At 20 megapixels, the resolution with an aspect ratio of 4:3 is 5152 x 3864 pixels. At 300 dpi, this results in a calculated print size of 44 x 33 cm.
Source: https://de.wikipedia.org/wiki/Bildaufl%C3%B6sungen_in_der_Digitalfotografie

If the resolution of a photo is too low for a particular place holder we will indicate this with a red bar. Empty picture boxes will be accompanied by information on which resolution is recommended to achieve optimal print results. Scanned pictures should have a resolution of at least 300 dpi although 600 dpi is recommended for best results.