Abstract: Foam plastics sheet material, such as a wallcovering, has a pronounced decorative relief finish and comprises a substrate web with a foam coating some at least of which is blistered. The blistering is achieved by having two foamable coatings on the web, the lower of which is sacrificed to produce the blistering in the upper. In one method the lower coating is foamed, the upper coating is then applied in its pre-foamed state, and then heated so that the lower coating is sacrificed and the upper coating is foamed and blistered. In another method both coatings are applied in their unfoamed state with the lower coating having a lower foaming temperature than that of the upper coating. Both coatings are then heated together. The lower coating foams and is then sacrificed. The upper coating foams and blisters.

Abstract: A process for the manufacture of a differentially expanded sheet material comprises applying an organic solvent to the surface of an expandable thermoplastic sheet containing a blowing agent and allowing the treated sheet to at least partially dry before a composition comprising an ink and a kicker for the blowing agent is applied to selected areas of the treated surface. The sheet is then heated so that differential expansion occurs.