diluted just before the use on a printing substrate which is preferably printing paper ranging from 80 to 450 gr m 2 but that in specific cases could also be cardboard canvas wood or other material the mixture is applied so that an even thickness is obtained for instance by machines using rollers pads blades or the like or also by spraying devices just after the mixture has been applied the substrate is passed through contact means suitable for improving the adhesion of the coating to the substrate and also useful to promote the creation of random patterns which are mainly due to the material of which said contact means are made and to the composition and viscosity of the mixture for instance in a specific embodiment a soft unsmooth roller preferably a sponge is passed on the surface of the mixture for making the surface even and creating a texture whose depth and pattern are due to the pattern on the surface of the roller to its elasticity and to the consistency of the mixture alternatively if the mixture is sprayed on the substrate the sponge roller can be avoided as the mixture could already have the suitable roughness the substrate is then dried in a aired environment with humidity under control and after about 5 minutes it is obtained a.