When Tom's art appeared everything up to that time became pale by comparison.
"I work very hard to make sure that the men I draw
having sex are proud men having happy sex."
That statement truly sums up why his work had the impact it did. Tom's men were like jets compared to biplanes. Not only were they bigger than life physically, but their sheer macho, swaggering bravado made them into sexual heroes the like of which had never been seen before by gays starving for visual stimulation. At last, images of men made to masturbate to the way minuet music was meant for dance.
There is no possible way to accurately measure the impact of Tom of Finland. But there is this yardstick: just take a look at male homoerotic art now and you will find his influence almost everywhere.
Tom made men with impossible phalli not just acceptable but de rigueur. His men were not hothouse flowers or innocent fauns, they were cowboys, sailors, soldiers, men in black leather drag on motorcycles; all hyper-masculine he-men bursting with testosterone driven goodness. They were handsome, yet rough with 5 o'clock shadows, and clothing that looked like if it were any tighter it would burst and release a flood of pure masculinity. You could put those impossible cocks over a shoulder and burp the damn things. These male characters were to gay men what Superman had been to young boys of the late 30's. To dream the impossible dream and cream over him.
So, if you love male art as much as I do and enjoy the now large field of very out and up front homoerotic cartoonists/illustrators (Patrick Fillion, Logan, Rob Clarke, Absolut Bleu, Joe Phillips, etc.), the man you have to thank for helping to make a place in society for such work is definitely Tom of Finland. He didn't just blaze a trail he created a jet stream or a super hiway into the great gay milky way.