Abstract: Flat cooking-vessel bottom the outer surface of which is provided with equidistant concentric grooves in the form of circles and coated with two overlying layers the first of which is in contact with the metal and consists of a material with, high radiation heat absorption capacity distributed uniformly over the entire bottom surface and the second layer consists of an enamel or silk-screen paste resistant to abrasion and scratching distributed nonuniformly and preferably in segments and only on the lands between the surface grooves.