 PITTSBURGH, May 17, 2021 PRNewswire -- Koppers Holdings Inc. NYSE: KOP, an integrated global provider of treated wood products, wood treatment chemicals, and carbon compounds, has published an enhanced digital 2020 Annual Report on its website, featuring CEO Leroy Balls letter to shareholders highlighting the companys strategy, operations, and financial performance. The events of 2020 brought a number of undeniable strengths to the forefront for Koppers, even amid the challenges associated with the COVID-19 pandemic. 