Mylar. Mylar offers excellent EMF shielding when placed between you and the radiation source. It's important to note, however, that the goal of protecting you and your loved ones against the harmful effects of radiation isn't to block it by 100% but to reduce it by at least 90%.

What material can block EMF?

Typical materials used for electromagnetic shielding include sheet metal, metal screen, and metal foam. Common sheet metals for shielding include copper, brass, nickel, silver, steel, and tin.

Does Mylar reflect RF?

RF: Radio waves and microwaves can be reflected off a metal sheet in exactly the same way that light reflects from a mirror. ... Therefore, aluminum foil, aluminum screen door material (or metal mesh), or even Mylar space blankets* will reflect radio waves.