Not to be the devil on your shoulder or anything, but that really looks/sounds like PEI to me. Especially since you have to use tape to adhere it on. Don't know much about Industrial supply in the UK, but you can get the stuff through Mcmaster carr or amazon in the US for significantly cheaper.
I did a review of a type of PEI build surface that came pre-backed with adhesive. I got the samples a few months ago, and really put them through the ringer so far, with multiple prints a day with no seeable issues. You can see the video here. https://www.youtube.com/watch?v=uGkE8faPmh0 Or you may have seen it here on my old channel https://www.youtube.com/watch?v=JJd0_lcbiMA
Not saying for absolute, but from the pictures vs. the video, you can see why I came to this conclusion.
I don't know, you may want to check it out, is all I'm saying.