This doesn't help you but I sympathise.
When I bought my six foot tank early last year I used a removeable sealing compound to stick my black backing on the the outside of my tank. I got it all into place and filled the tank with 640 litres of water, decorated it, planted it and stocked it with fish -- all fine. Until about six weeks had passed then without warning, right in the middle of the backing paper from the top to the bottom of the tank, the paper pulled away from the tank leaving a strip about an inch wide that was a different black -- gloss as opposed to matt. The tank with water, gravel and decorations probably weighs about 800 Kg so it's not going to be moved in a hurry.
I thought of all sorts of ways I could cure the problem from slitting the paper and making a less visible fold or pulling the paper from the side and then trying to stick it back on, neither of which was viable since there was only three inches of clearance between tank and wall.
So what did I do? Bought a plant, a tall one, one that when fully grown has leaves that stick out about the water and has a copious number of stems -- I can hardly see it now.
And for your information in case you buy a very large tank in the future: The reason the paper pulled away was because I applied the paper on to a cool, empty tank and when the water warmed and everything stabilzed the paper expanded and finally gave up the sticky ghost and came away.