Progression 21-A , by abraham palatnik , 1965 , abstract , Op Art style , Brown, Pattern
A wall made out of wood blocks with different patterns.
 a wood grain pattern. The wood grain is light brown. The pattern is wavy. The lines on the wood grain are black. The black lines are wavy as well. There are squares in the pattern that are made up of the same wood grain. The squares are equal in size. The surface of the wood is smooth and polished.