The look of a page printed by plone is ok and neutral thanks print.css. It would be rather handy to have a diazo rule which switchs off theming in the case that the page is printed (that the demanding device is a printer).
<notheme if="$print" />
But how to define $print in manifest.cfg?
Unless you want to have a specific print URL, that won't work. print.css works at the browser/css level. The server doesn't even know, and the page isn't even reloaded.
I think the general consensus is that CSS is the right way to do this. So, stick with that strategy unless you have very unusual requirements.