Verity,
As a layman er... sorry, layperson, I have to say your logo looks pretty good already. You can possibly add something to emphasize the liquidity of the large ink blot.
http://www.geocities.com/withmyluckt...ken/blotty.gif (the link is a bit temperamental, so try copying it into a new browser window - I suppose they don't like referential linking!)
I think the bevel might be a tad too harsh in my example.
You can also try to soften any hard edges for letters inside the blot since naturally the surface tension of the ink/fluid pulls it into more curvy shapes. It can happen though that some sharper corners remain (from what I can remember of my leaky pen days) due to the texture of the paper. Who knows, maybe you can buy a cheap pen/some ink from a local stationery store and make a blot on a piece of paper - there's no better example than reality.
P.S. If you really want to jazz it up, I suggest listening to some Miles Davis while looking at it.