Blanket or slab for overprint varnishing

A blanket or slab for overprint varnishing comprising at least a varnishing layer and a single-layer or multilayer support of uniform thickness, wherein the varnishing layer is made of non-cross-linked thermoplastic elastomeric polymer, wherein the varnishing layer envisages the presence of non-image areas where no transfer of varnish takes place, wherein the non-image areas are areas of the varnishing layer that lack material and extend from the outer surface of the varnishing layer to a depth which is no less than half the thickness of the varnishing layer, wherein at least one non-image area delineates a geometric shape having an area of less than 5 mm2 and wherein said varnishing layer having non-image areas is a physical reproduction of a digital model obtained with additive technology.