Could you include the Stiftung Warentest winners in your range?
For bedrooms in the attic, the testers strongly recommend highly reflective films - which were the front-runners with an average score of 2.2: Bruxsafol (AX Plus 20) Opalfilm (silver 20R sr Primus Plus) For those who prefer it brighter, less highly reflective films are recommended. Here, the best performed with a grade of 2.2: Bruxsafol (AX Plus 70) Llumar (CHE 55 ER)
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