L Emi 4 I bought it thinking it was polystyrene. But it is something a little different, and the tape or glue doesn’t work on it (depending the type of tape).I wanted to assemble them to make some window panels. My aim was to use the panels for the night, to cut the lights and noise from outside in addition with curtains. I assembled them with a lot of plastic tape (the paper one is not sticking on it), and I put a dark wall paper on one side that I fixed with tape again (the glue was useless). It is not really fancy to look but it makes the job.It is good at keeping humidity away.