All the boards are produced in moulds. To prevent surface damage when the boards are removed from the moulds, a release agent is used. Some of this release agent remains on the boards. As the boards weather naturally, this will dissipate. Depending on weather conditions, this could take 4-6 weeks. The process can be sped up by cleaning the boards with warm soapy water and a hard brush (sometimes it is necessary to repeat this several times to get the desired result).