The Baader Solar Film - 250mm x 250mm - Visual Use from Astrozap: Baader Planetarium's AstroSolar safety film from Astrozap size 250mm x 250mm (9.84-inches/square) is a specially manufactured streak- and blister-free foil. It attains the optical performance of plane-parallel glass filters. The base material is not Mylar! The basic development of this film was made in laboratories for nuclear- and particle physics.
High-density coatings on both sides of the Astrozap Baader Solar Film ensure highly uniform filtering while neutralizing the occasional microscopic holes in the coating. The image of the sun is extremely contrasty and of almost neutral color. The coating of the foil is subject to constant quality control.