Decorative HPLs with melamine surfaces are supplied in the form of panels. HPLs essentially consist of paper and thermosetting synthetic resins; the paper represents more than 60% of the product, while the remaining 30-40% consists of polymerised melamine resin for the decorative surface layer and of polymerised phenolic resin for the underlying layer. During the process of polymerization in high pressure and temperature conditions, three-dimensional chemical bonds are formed that result in a stable, non-reactive material with characteristics that are completely different from those of the individual raw materials.