PURPOSE: To automatically and easily form non-regular and decorative patterns on a fabric by repeatedly spraying a dye solution by a dye solution-spraying means moving to be reciprocating orthogonal to the transport direction in which the fabric is moved.

CONSTITUTION: This method of producing color spots in repetitive, non-regular patterns on a fabric layer is to lay a fabric 1 drawn out of a feed roll on a conveyor belt 2 and spray a dye solution on the fabric from spray nozzles 10 through a flexible pipe 11 from a dye solution storage tank 14 during transporting the fabric under the spray device at a constant velocity. In the mean while, the dye solution is repeatedly sprayed on the fabric moving forward by mutually moving a rotating rod 6 and a connected slider 5. Thus, color spots having irregular sizes and shapes are repeatedly formed to automatically apply irregular and decorative patterns.