An amateurish theoretical approach: (thinking in RGB-colors): Your brightest white on the Al is not a 255,255,255 but perhaps a mere 160,160,160.
So you have to optimise the picture to that reduced “dynamic grey space”. I think increasing contrast on your screen (which shows almost all the way from 0,0,0 to 255,255,255 then is the wrong way? (Instead, optimise the picture to a max white level of 160,160,160 or to whatever grey level the Al surface has) Or would this be the task of a printer profile?