"inferior, cheap material," 1962 (in song "Little Boxes" by U.S. political folk-singer Malvina Reynolds, 1900-1978), reduplication of tacky. As an adjective by 1967.
Entries linking to ticky-tacky
tacky adj.1
"sticky," 1788, from tack (n.1) in the sense of "an act of attaching temporarily" + -y (2). Related: Tackiness "stickiness."