On some searching around Ebay for heat tape, I discovered it is actually called Polymide tape or Kaptop tape. I'd known that the tape we all use isn't really specific to sublimation use, and must have a wider industrial purpose, and so I am glas to find out what the product is actually called.
Not had a chance to check the pricing to see if we're paying more for buying "sublimation tape" as opposed to just plain polymide tape yet though.
I also noticed that there is a lot more choice in roll lengths and thicknesses when searching the generic product.