thank you very much for your answers and your links. now i know a little more about dpi a.s.o., although this is not so easy to understand.
but my main-problem still exists: how can i arrange my fotos in a row: 3 in the first row,
3 in the second and so on. when i copy a foto (e.g. 10 x 8 cm) into the defined layer (e.g. 80 x 80 cm), it will be as big as the layer and there is no space for another foto. if i resize the foto first, will its print-size change, too?
thank you for your patience.
peter d.