Following up on Luc(as) de Groot’s experiment of alternating typefaces in every other paragraph of a newspaper, I threw together letters from both Univers and Helvetica and did some scaling. I used the open source versions of the fonts by URW.
The Aladdin Free Public License applies.
Remarkably, to me the result looks more like Univers than Helvetica, and on Windows the hinting helps a bit to unify the appearance. Because of the different stem widths and weird spacing, in print it has the feel of an irregular typewriter or rub-down lettering face.
Check it out for yourself: http://www.kutilek.de/download/helvers.zip