You seem to have posted this at every LF site on the web and I've answered it twice elsewhere but for the benefit of those who only look here - the tape doesn't keep out light, it isn't there for that purpose, the only purpose of the tape is to serve as a hinge for the flap, so light leaks won't be fixed by replacing the tape. Also, no special tape is required for a film holder, any tape will work fine as long as it holds the flap securely, is sufficiently flexible and (if you photograph in extreme heat) won't gum up. There are many many kinds of tape that will meet these minimal criteria, most of which can be found at your local drugstore.