A colleague of mine is a passinate butterfly observer. So he brought me some tulle and gave me instructions to make him a net for observation. He also gave me a circle made of strong flat wire.
I sewed the long sides together with a flat seam, then the upper part and finally made a tunnel - just in an easy way, folding the fabric and sewing 0.7 from the edge.
If I understood it correctly, he should hang this thing, turn on some light inside it and watch the butterflies sit on the net. Charming!
