Well, I've got black silicone, rockoflex and other goodies coming. Skint now tho so shall be getting the background designed and made but not finished with the plastidip and tree fern substrate till I get paid, gonna get a thread on the go once its here and I get pics of it etc

DC, its quite popular in the UK for doing backgrounds when applied to either a rockoflex or expanding foam. But I do have the same concerns as you, apparently it is easy to peel off metal and plastic when you want to change it. Maybe its reaction with expanding foam or rockoflex is difference