Ink question...

[kixeldorado.livejournal.com]

Okay, this might be a little bit more art related than craft, but I'll ask anyway and I might get lucky.

I've got the idea to do a picture on a (gessoed) canvas with brush and ink.
The ink that I've got is "Higgins Black Magic" ink, it says it's waterproof. Nonetheless, when I get done, I want to protect the piece somehow.

I've seen varnish for oil and acrylic paintings in stores, and eventually I might get some because I've got some paintings almost done.

Would this use for an ink piece? The ink says waterproof which of course means that it's not soluble with water, but what about the oils or whatever is in the varnish?

Has anybody tried this before?
Is there an alternative solution? (Yeah, put it under glass, but framing's more expensive than I have money for...and a little bottle of varnish is much cheaper than a big ol' frame set.)

Anybody?