I have read in various places, mostly forums, that one should use only one brand of tape -- never changing, because differences in manufacturers' particles/lubricants/substrate/or something will cause damage or at least "gumming up" of video heads. Is this an actual fact? Does anybody know of a credible technical reference that describes this phenomenon? Has anybody ever had this happen? Is this why the Fuji tapes didn't work well for me, or was that something else? Or is this the tech equivalent of urban legend -- a fact "everybody" knows but nobody knows where it comes from? Thanks, everyone! PS: I DID search for this answer! PPS: Sorry, I misspelled "is" in the title!