[TxMt] Modding TM's built-in browser

I do almost all my writing in TM these days, using MultiMarkdown, and then simply preview using the built-in browser to get pretty pages to print when I need to. The built-in browser does a great job of respecting left and right margins as set in style sheet, but it cares not one whit for top and bottom margins and so when I print I get text that starts at the very top and runs to the very bottom of the page. Is there a way to change this within my little TM universe? Outputting to a browser like Safari means I get all of Safari's headers and footers, which I don't need.

john