which side of this reflective material faces out?

Picked this up at a local hydro store and tried to find more info online but found out its been discontinued for a while. Looks like some pretty good stuff. Which side should I face out? The inside of the role is a little more dull and you can see the threads but the outside is more aesthetically pleasing but its shiny so hot spots?

the shiny side??

i kid, i kid, but there seriously should be a more mate side and a shinier side.. mate side in..

if both sides are shinny . then put the ruff side out . reason for that to avoid hot spots .