Anyone for Frottage

Remember that beautiful stretch of lepidodendron fossil we 'rescued' from the beach last week?
Did some frottage from it today and embedded it in my latest encaustic piece. Frottage collaged. Heh. Thank goodness for the French language.
Frottage
http://www.tate.org.uk/art/art-terms/f/frottage
from the French verb - frottere, to rub.
Side view in extra today.
See Max Ernst's work for some proper frottage
Yes it does have some usage in sexual parlance - but trust me - this was for artistic purposes only today.