NBN EN 663:1995

This European Standard specifies three methods for determining conventional pattern depth by change in appearance of the characteristics of the pattern of resilient floor coverings which are classified as follows: Group 1: Patterns where the different bands (in colour and/or relief) are distributed in a uniform manner, wher the ration of pattern to background in small areas of 0,01 m2 to 0,02 m2 in not more than 1:4; Group 2: Patterns where this ration varies considerably where some areas of 0,01 m2 to 0,02 m2 may contain only one part of the pattern.