Abstract: Printing image carriers for surface printing which have a water accepting surface adapted to have ink accepting surface elements transferred to it by the action of heat and pressure. In order to ensure reliable transfer of such layers keeping to precisely delimited outlines the printing image carrier is of a material which is thermally insulating and whose surface accepts water. The result is the avoidance of excessively rapid conduction away of the heat input from a pressing head which would otherwise be likely to interfere with a precisely delimited transfer of an oleophilic layer or to generally prevent the application of such a layer.

Abstract: A cavity receiver having an aperture through which concentrated solar radiation enters the cavity. Holes are provided in the bottom wall of the receiver through which cold air, which enters the cavity through the aperture, can be withdrawn by an aspirator. The outlet of the aspirator can exhaust the cold air to the atmosphere, or reintroduce the air into the cavity through holes adjacent to the aperture. Holes can also be provided in the top wall of the receiver, and an aspirator used to withdraw air from the cavity through the top wall holes and reintroduce it into the cavity through the bottom wall holes.