I recently purchased a large number of plug plants (by mail order), potted
them on and carefully labelled them all. Went into the glasshouse today and
found that less than a week later, all the labelling had faded to zero - I
assume it was a combination of heat (80F in glasshouse today) and sun .
Fortunately I had kept the original trays and eventually fathomed out which
plants were which. Have bought some more "guaranteed non-fade" pens today
and am keeping my fingers crossed.

Jeanne