the color is only on one side, one side black one side silver, very stiff does not stretch black side feels like counting of plastic
Mobile signal of my phone dropped to minimum (but was still present) when wrapped in multiple layers of the fabric. Wi-Fi : my local 2.4 and 5GHz signal also decreased, but still was present. All Wi-Fi signals that were not from my house disappeared (I have like 20 or more visible routers from my neighbors with various strength, all were gone) Wrapped my Wi-Fi router in multiple layers of the fabric (had 4 x 1 meters to my disposal :D) again, the signal was weaker, but did not disappear. If nothing else, it definitely weakens radio signals (wifi/ mobile network), so I used it to cover the children's beds, and after just two days, they are full of energy and first time in many years they are lively and happy after they wake up.