市松 ・ いちまつ ・ ichimatsu
A checkered pattern. Originally called ishidatami (石畳) since the pattern looks like a (cobble)stone pavement. A continuous, uninterrupted pattern of squares that is associated with eternity and prosperity. The pattern can be used with plain alternating colored squares or with the pattern creating square spaces for different designs.
It started to get called ichimatsu after the Edo era kabuki actor Sanokawa Ichimatsu (佐野川市松) wore the design on his costume.
The pattern can be combined with different design t make new designs. One combination is ichimatsu-hanabishi (市松花菱), where alternating squares are replaced with a (rotated) hanabishi (flower) design.