Requirements: some brassicas and several cabbage white butterflies.
Outcome: a week or two later . . . natural green lace.
Husband, looking at these, wails, "Oh my poor cabbages!" (purple sprouting broccoli in fact). And didn't I knock the caterpillars off? Well, no, actually, they seemed quite happy. But now with a bit of technological wizardry the broccoli looks even more interesting. Though I'm not sure I'd want to eat it. May be time though to get the fabric out, and perhaps the heat gun calls.
Many thanks to Jenny, fellow blogger, for collaging these pics for me with her software.