Mich. Comp. Laws § 257.226c

Sec. 226c. Beginning with the registration plates manufactured in the year 1970 and succeeding years they shall be treated with an effective and dependable reflective material according to specifications promulgated by the department of administration in conjunction with the department of state highways, the department of state and the department of corrections. In any year during which registration plates are not furnished, the department shall furnish for each annual registration a reflective tab or sticker designating the year of registration.