Impact copolymer polypropylenes (ICP) are quickly becoming the interior trim resin of choice because of their low cost, low density, ease of processing, and the ability to recycle. Included with these advantages, ICP offers excellent part appearance right out of the mold along with good mechanical performance. A successful ICP interior trim part is one that meets all appearance and performance requirements, as determined by the OEMs and their full-service suppliers. Both part design and resin properties/characteristics play crucial roles in arriving at successful parts. The design of the part must reflect the properties of the ICP to achieve optimal appearance and performance.Some important guidelines and considerations are presented to ensure the desired performance in ICP part appearance and performance.