On a shiny-bright gutter sample from Joseph Cazeault, master metal-smith of
Martha's Vineyard (100 running feet of copper gutter = $3000), I made
separate daubs of ketchup, mustard, sweet relish, tartar sauce, canola mayo,
buttermilk, regular mayo, orange juice [note to Mary: with pulp], and organic
"lite" mayo.

After 8 hours (I went to the beach) there were green rims of smudge around
the mayo, buttermilk, ketchup and some others, but when I rinsed everything
off, all the green patina washed off and the end result was that all the
applied materials had brightened, not patinated, the copper - it looked like
a freshly minted penny.

So, what's all this stuff about mayo-patination of architectural copper?

Sign me,  Not Too Bright