Now completely unconnected to this, I gave my parents an environmental art calendar last Christmas. One of the photos was of a leaf, with a mathematical formula carefully etched into the leaf so that it could be seen when held up to the light.
Immediately the MI5 agent within me woke up and sprung into action. For a while now I have been experimenting with thorns, needles and leaves to see what would work and without much success most of the time.
Most leaves were not the right consistency and would break, or would close up or would just be downright difficult when used in this way.
And then one evening, as I had nothing better to do, I thought I’d have a go with a cocktail stick and some of the large nasturtium leaves, from my own back garden.
Hey presto! The back of the leaves are a perfect etching surface. The leaf texture is soft so it’s a case of bruising the leaves. I think this would be a little too tricky for young children but an excellent challenge for older ones.
Next, the trick is to be able to hide the leaves so that only other spies can recognise it!
Sadly, I kept taking fuzzy photos of the leaf when held up to the light. So here’s another nasturtium leaf to give you an idea…
I think this idea has potential to be used in all sorts of fun and interesting ways. Not least, because, if you want to get rid of the evidence, you can eat the leaf! They do taste better young and fresh, though.