Abstract: The invention relates to a process for preparing thermoplastic sheets or webs suitable for use as surfacing materials.Sheets of thermoplastic polymers are known as surfacing materials and, when foamed, as substitutes for wood, but available materials do not closely resemble natural wood in appearance. The present invention provides a process whereby sheets or webs are obtained which can provide a wide variety of decorative finishes and which can approximate the appearance of such natural products as wood and marble.The process of the invention comprises the extrusion of a foamable mixture of immiscible thermoplastic polymers, one of which is crystalline and of higher melting point than another, stretching the resulting foamed extrudate, compressing the stretched extrudate and then cooling the stretched and compressed extrudate. The resulting product is substantially impermeable and has integral patterning and can be used as a surfacing material in a variety of applications.