To add to the growing body of literature on "whiteout"...
 
Last Friday (OK at Happy Hour), I was describing the recent discussions on
whiteout seen here.  A colleague followed with his recent experiences.  It
seems hehas been using a water-based type of whiteout for correcting
blueprints. At thend of each day the blueprints would be piled on his desk and
in the morning when he came in the whiteout lines that were exposed would be
gone.  Those underneath would be fine.  It happened each night for several
days. One closer examination he found there was a sort of faint fuzzy line
left on the paper.
 
Anybody guessed what caused "deterioration" of the whiteout?
It was cockroaches.  Every night they would come out and eat the
exposed whiteout lines.  It was a brand that was tempra based.
 
One more fun fact to keep in mind.
 
Jessie Johnson
Texas Memorial Museum