i debated whether i should paint an envelope or hills that are enveloped in fog. but the prompt says 'envelope' (with an 'e' at the end) which means that piece of paper folded just so to put in one's correspondence. until i reached high school (that was a long long time ago), i struggled with envelope and envelop. of course they are pronounced differently but i see that in my old age, i could still get confused with those two words.
world watercolor month's prompt for today is "envelope".