piwigo/themes/default/print.css

#menubar, .content .navigationBar, UL.categoryActions, .content DIV.calendarViews, .calendarBar,
#imageToolBar, .navThumb, #addComment {
    display: none;
}

BODY {
    margin: 0;
    color: #000000;
    background: #ffffff;
}

.content {
    margin: 0;
}