We desperately needed a solution for our slices of balcony doors, where all summer long at lunchtime in the sun is beating the living room and heats powerfully. Quite often we have evening then 30 ° - with longer heat waves even more. My husband is very skilled craftsmanship and has just given to the application. In the first disc we had in advance when cutting has many kinks, because we have not come up with the idea to use a larger table. Accordingly, many dents that had to be knife-coated were then available. In the second plate, my husband has the kitchen table undressed correspondingly large and slightly moistened, that the film has remained smooth stick. Then cut and peeled off the backing and equally well sprayed with a vegetable spray the foil. Then they stayed on the also slightly damp disc almost stick smooth by itself - you needed to align just a bissl. A little tip: the flattening works better with a squeegee :-) The room is only slightly obscured and from the outside can not see inside - it acts like a mirror. Whether there is a corresponding effect, which keeps the heat outside I can probably judge next week because it is well over 30 ° are ... But every degree less for us is already a profit. A star deduction I was due to the heavy removability, we just noticed from other reviews. So better not settle ;-)