Parchment paper and bakery release paper, are cellulose-based papers that are used as a disposable non-stick surface intended for use in baking. Both are also called bakery paper.
Modern parchment paper is made by running sheets of paper pulp through a bath of sulfuric acid (a method similar to how tracing paper is made) or sometimes zinc chloride. This process partially dissolves or gelatinizes the paper, which is reversed by washing the chemicals off followed by drying. This forms a sulfurized, cross-linked material with high density, stability and heat resistance and low surface energy which imparts good non-stick or release properties. This process gives the paper an appearance similar to traditional parchment.