(under subclass 443) Structure wherein (1) the backing member has a groove formed in a face thereof or (2) a groove formed by a configuration of the abutting edges of plural backers, said grooves serving to aid in retaining the settable material.
SEE OR SEARCH THIS CLASS, SUBCLASS:
450+, for a corrugated backing member.
605, for another module with grooves on a juncture surface.
SEE OR SEARCH CLASS
428, Stock Material or Miscellaneous Articles,
163, and 167+ for a stock material for that class having a component which varies in thickness in the form of parallel ribs or grooves.
