This 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 where the ratio of pattern to background in small areas of 0,01 m2 to 0,02 m2 is not more than 1:4. Group 2: Patterns where this ratio varies considerably where some areas of 0,01 m2 to 0,02 m2 may contain only one part of the pattern.