Parkside Copper Tape / Mesh £4.99 @ Lidl

Tried this last year, it kinda works but it won't keep them all out. Some brave it for the rewards, usually the big fat ones. I found it worked best when new and shiney, but as time went on and it dulled, plus the trails from other slugs that went over it then wasn't so effective. Worth doing though I'd say, but be sure to leave a big gap between pots and move further apart when the plants grow big or they just use the touching leaves as a slug highway. (edited)