Otto Kuhni began freelance work in 1962, including some projects for Mattel that predated his involvement with Hot Wheels, which began in 1967. First, doing art for the original blistercard and many of the collector's buttons, play sets, accessory packages for tracks, curves, jumps, loops and double loops, etc. 1968-1970 were busy years, illustrating larger play sets, more blistercards and buttons. There was also art for many Collector Cases, including 12, 24, 48 and 72 car cases. He did many of the Hot Wheels blistercard and collector set illustrations through 1995.
   
During this time, he was also freelancing for Lockheed, McDonald Douglas, Hughes, JPL, Max Factor, J. Walter Thompson, L.M. Cox, Challenge Publications, Graphic Films, Entex, among others. During a number of years when he wasn't working for Mattel, he did work for Galoob, Tyco and Playtime. Towards the end of his career and before passing away, Kuhni returned to work on Hot Wheels.

Blistercards

Basic Redlines, Heavyweights, Spoilers, Grand Prix Series, 1972 package, 1973 package, Revvers, Rrrumblers, Hot Shots, Flying Colors, Mega Force, Super Chrome, Scorchers, Crack-Ups, Hi Rakers, Workhorses, Flip-Outs, Color Racers, Hot Line Train Stunt Ratz, Park 'n' Plates, California Customs, Hot Birds, Speed Demons
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Accessories

Jump and Parachute, 180 Degree Curve, Rod Runner, Trestle Bridge, Dual Eliminator, Danger Changer, Talking Garage, Speed Test, Victory Pak, Starting Gate, Tune-Up Tower, Turbocharger, Speed Shop, Service Station, Speedometer, Dual-Lane Speedometer, Supercharger Double and Single, Hot Wheels Injector, Dual-Lane Rod Runner, Dual-Lane Lap Counter

Sets

Strip Action, Stunt Action, Super Charger Sprint, Double-Dare Rod Runner