The present invention comprises a mold having a wall with a recess defined therein and magnetic means, wherein an associated insert is adapted to be selectively held within the recess via the magnetic means, such that the insert is substantially flush with the wall. Using the magnetic inserts in both the upper and lower mold halves results in a tire identification number being imprinted on both sides of a tire during a curing cycle. The inserts are easily and quickly changed so that down time during production is minimized, tire appearance is improved, and eliminates tire scrap.