Hello, after trying several other places I hope to find an open ear for this issue here. I stepped on this in the german wikipedia, but its the same in the english and probaly others:
The stylesheet for printing is called via: <link rel="stylesheet" type="text/css" media="print" href="/skins-1.5/common/commonPrint.css?41" />
Now for the mostly relevant style it contains a fixed font size: #content { .. font-size: 11pt; .. }
The effect is that a print page can not be scaled prior to printing, as for example in Firefox. Fixed font size reduces the accessability and IMHO makes sense only for printing on fixed paper forms.
The simple solution would be to replace the '11pt' with a percent or em-Value that renders similar in popular browsers, like '92%'.
There are other issues with commonPrint.css (like: why should it not be appropriate to have the Wikipedia logo on a printed Wikipedia page?), so as a second step I would propose an option in the user parameters "Turn off specialized stylesheet for printing".
But let us clarify the fixed font issue first.
Greetings // Bernd