Abstract: A fibrous substrate material for producing a porous coating base paper or prepreg comprises a planar impregnatable structure made of cellulose fibers, which contains at least one pigment species and optionally contains further additives conventional for paper. The cellulose fibers contain a proportion of 1 to 20 wt.-% of nanofibrillated cellulose (NFC). A method for producing the fibrous substrate material comprises the steps of: providing an aqueous suspension containing a cellulose containing material and an admixture of said pigment species and, optionally, further additives conventional for paper, sheet forming, drying. The cellulose containing material contains a proportion of 1 to 20 wt.-% of NFC with a specific surface (SSA) of at least 125 m2/g.

Abstract: A fibrous substrate material for producing a porous coating base paper or prepreg comprises a planar impregnatable structure made of cellulose fibers, which contains at least one pigment species and optionally contains further additives conventional for paper. The cellulose fibers contain a proportion of 1 to 20 wt.-% of nanofibrillated cellulose (NFC). A method for producing the fibrous substrate material comprises the steps of: providing an aqueous suspension containing a cellulose containing material and an admixture of said pigment species and, optionally, further additives conventional for paper, sheet forming, drying. The cellulose containing material contains a proportion of 1 to 20 wt.-% of NFC with a specific surface (SSA) of at least 125 m2/g.

Abstract: An improved method and an improved device for carrying out an optical comparison between at least two samples, preferably by comparing sections that can be selected, is characterized by the following characteristics: the sample (UR, LE, I) that is to be examined and is characterized by a non-uniformity in the structure and/or color is illuminated by diffused light; from the light reflected by the sample (UR, LE, I) to be examined, an interference spectrum is created by means of a spectrometer; the interference spectrum created by the spectrometer is depicted on a camera; the interference spectrum obtained in this way and/or values of the sample (I) to be examined derived therefrom are used as sample values which are compared to sample values of a reference sample (UR, LE) obtained accordingly.

Abstract: An improved method and an improved device for carrying out an optical comparison between at least two samples, preferably by comparing sections that can be selected, is characterized by the following characteristics: the sample (UR, LE, I) that is to be examined and is characterized by a non-uniformity in the structure and/or color is illuminated by diffused light; from the light reflected by the sample (UR, LE, I) to be examined, an interference spectrum is created by means of a spectrometer; the interference spectrum created by the spectrometer is depicted on a camera; the interference spectrum obtained in this way and/or values of the sample (I) to be examined derived therefrom are used as sample values which are compared to sample values of a reference sample (UR, LE) obtained accordingly.