Yuzet Radiator Heat Reflective Insulating Foil, Energy Saving, Reduces Heat Loss, Easy DIY Fitting. Pack of 6 - 0.6m x 5m Per Roll

Cut out and used to hang over the radiator brackets and secured it to the wall with double sided sticky tape. This was okay in the short term but when it got hot it’s sagged. I decided to attach two very thin hardboard and use it this way. I was able to wrap it over the hardboard and secure it tightly. This was then hung over the radiator brackets so far so good.

Only time will tell if this helps deflect heat back into the room but excellent value for money and was very easy to fit behind radiators. I haven't bothered with sticking to the wall, just cut to the right length and then cut 2 slits up each side and slotted behind the radiator, letting the sheet rest on the top of the brackets. Very pleased with this product!

Works well keeping warm easy to fit, adhesive could be stronger but it worked fine, would highly recommend