What is the importance of grain direction in printing ?
Papers and paperboards are anisotropic i.e they show different values for a same property in their orientation for e.g they expand more across the grain than along the grain direction. So the feeding in the printing machine is such a way that the grain direction is perpendicular to the feeding direction. This facilitates good feeding. Also the print length can be adjusted by changing the packing under blanket or plate cylinder. By adjsuting this the misregister caused due to the expansion or contraction of paper can be corrected.
