[Eightball]

6mm might not be wide enough though. I have a double row of 30mm copper tape. I watched a snail try to bridge over it but thankfully the tape was wide enough that he couldn't make it. He got approx 15-20mm over the tape before having to even touch the copper. It wasn't a huge snail either so I reckon a big snail/slug might be able to bridge further. It did work though. Once it touched the copper tape it retreated