Car Tire Marker

It's again 'that' time of the year. The summer tires have to be changed for the winter ones. Until now I always marked my tires with chalk, only to spend hours of deciphering six month later wit a good portion of estimation and sheer guessing.
But no more! This time I made some tire markers that fit on the valves and say cleary FR, FL, RR, RL. If I still mix them up next spring, I got bigger problems than misreading my own marks.