To provide a method for adding a pleat pattern to a triacetate blended yarn knitted fabric by a pleat processing method and further applying a stable opal processing to the fabric, and to provide the pleat pattern fabric by the method.

This method for producing a pleat pattern fabric subjected to an opal processing comprises heating a blended yarn knitted fabric comprising 70% of triacetate fibers and 30% of polyester fibers in a dry state to arrange stitches, superposing an opal processing 3 pattern screen on the stitch-arranged knitted fabric under the consideration of a width contraction to be caused by the subsequent pleat processing 4, printing the knitted fabric with an opal processing paste for thermally dissolving the triacetate portions of the pattern in a stable state, preliminarily heating the printed fabric, subjecting the preliminarily treated fabric to a main dry thermal treatment at 180°C to carbonize the triacetate portions, washing out the opal processing agent with water, stopping the oxidation with an alkaline neutralizing agent, washing out the neutralizing agent with warm water, drying the treated fabric, and finally subjecting the fabric to a pleat processing by a conventional method. The opal processing agent is prepared by mixing a cut paste with a compound comprising a sulfate salt and a glycolic solvent.