There are a variety of license plate themes, personalized, environmental, special recognition and special interest license plates. Automobile, commercial and trailer license plate sizes are 12 x 6. Motorcycle license plate issued prior to July 1, 1970 are 8 x 5 and beginning on July 2, 1970 they are 7 x 4. California license plate are valid by affixing the month sticker in the upper left hand corner of the license plate and the year in the upper right hand corner of the license plate.