Having read John Kiernan's contribution in the January 1999 issue of Microscopy Today, I decided to add my two-cents worth (ignoring inflation), I have water-mounted preparations older than 5 years with no indications of threats to their permanence. The procedure is so simple it hardly bears writing about much less printing it for others to read.

I simply make sure any aqueous coversiip preparation on a microscope slide be dry at the edges of an otherwise full (of water) coverslip preparation, I simply add tiny amounts of water to completely fill the space between slide and coversiip, then wait a minute or two for the excess water on the slide outside the coversiip to evaporate. I can speed this step by wicking any excessive excess into a forceps-held small square of filter paper.