The present disclosure relates to extrusion coating systems, extrusion coated substrates, and processes for making the same. In some aspects, extrusion coating systems as described herein may include an at least partially insulated outlet wall, which may facilitate production of coated substrates exhibiting a very desirable surface texture and appearance. Coated substrates of the present invention may be utilized in a variety of end applications, including, but not limited to, interior and exterior construction materials for homes, buildings, and furniture.