originally i made up a stencil--- bought it in a construction tool supply store -- you could buy individual letters or numbers--or complete sets--they were somewhat expensive, maybe $1.50 each letter or number and sets were about $25.00.. the letters were about three inches high and they slide together and locked in place. i ordered the quantity necessary for my company's name and mounted them in an aluminum surround. i used it on ladders --gang boxes -- large tools -- scaffolds. i selected green and white as our colors and marked things with vertical stripes away from the stencil.. hand tools were marked with a etching tool and also sprayed green and white. i felt things needed to be identified from a good distance--------- from what i know--25 years in business i only know of loosing one battery operated drill set up -- and one complete gang box with a full setup of tools-knockouts,benders,drills,cords,sawzall,etc. which i knew who took it, just could never prove it. it was marked and chained to a 10 inch rain water leader. i thought i'd run into sooner or later, but never did---it had a set of expensive dolly tires on the gang box-- very unusual.. thats a pretty good record but your men are the people that control your thefts. i always wanted everything picked up and ladders chained up, including scraps and garbage--we prided ourselves on that--- in my mind it wasn't so much the cost of the tool --it was the labor lost until it was replaced????????