Copper collars for cabbage

Looks like it is getting warm but some mild weather is expected the next week. Today weeded the raised beds, sowed some pole beans and runner beans along the fence. Checked the cabbages and broccoli. Although I didn't find and snails or slugs I thought of adding a barrier. Since the copper mesh is expensive I thought of getting a few strips of  copper sheet from the guy who soldered our copper bird bath. He gave away a 2" strip of copper of about 3' length. I made a collar and inserted around the cabbage plants.