off a film and mask in consideration of the kind and content of a matting agent used and also in accordance with the rate at which photohardening proceeds by the action of a peroxide catalyst a preferred embodiment of the method of this invention for applying photohardening synthetic resin comprises the steps of first causing a photohardening synthetic resin such as unsaturated polyester resin mixed with a peroxide catalyst and if required a promoter to thoroughly seep into a sheet of paper and then applying a second layer of the same type of photohardening synthetic resin containing not only the above mentioned catalyst and promoter but also a matting agent and photosensitizer on said sheet of paper both layers of unsaturated polyester resin which contain a peroxide catalyst are effectively photohardened further the first applied unsaturated polyester resin layer which is free of a matting agent is saved from the difficulty with which a single layer of photohardening unsaturated polyester resin having a high viscosity due to the presence of a matting agent might seep into the tissue of paper thereby improving the toughness of the resin impregnated paper sheet since the matting agent is only contained in the subsequently applied photohardening resin layer the impact strength of a decorative panel is improved the second photohardening resin layer which does not seep into the paper tissue due to a high viscosity resulting from the presence of a matting agent elevates the embossed effect an expensive photosensitizer is only contained in said second photohardening resin layer contributing to the reduction of the cost of a decorative panel this invention will be moe fully understood by reference to the following example a 3 mm thick board of.