By Mark Savage
BBC News entertainment reporter
It is 49 years since Joseph Barbera and William Hanna made their first cartoon for television, a cat and dog caper called The Ruff and Reddy Show, but their work is still being shown around the world.
Hanna and Barbera won seven Oscars and eight Emmys
Characters like Scooby Doo and Fred Flintstone are icons of pop culture and their suspiciously similar catchphrases, Yabba-Dabba-Doo and Scooby-Dooby-Doo, have passed into common parlance.
In their 1960s heyday, Hanna-Barbera were delivering six hours of cartoons and live action programmes to US TV stations every week.
They had a global audience of more than 300 million people, and their shows were translated into more than 20 different languages.
Although there were other animation studios around, notably Filmation and DePatie-Freleng Enterprises, none of them could compete with Hanna-Barbera's roster of characters.
Among the studio's most enduring creations were Huckleberry Hound, whose TV show won an Emmy in 1960, and the "effectual, intellectual" Top Cat.
Stone Age hit
Hanna-Barbera was also responsible for Yogi Bear, Hong Kong Phooey, Wacky Races, Captain Caveman, The Jetsons and The Flintstones which, until the Simpsons, was the longest-running animated series to be shown on primetime TV.
The Stone Age sitcom was specifically created for a family audience in 1960, after a survey showed that more than half of Huckleberry Hound's audience were adults.
Portraying the bumbling adventures of everyday quarryman Fred Flintstone and his best friend Barney Rubble, the show was a huge hit.
The Flintstones were originally going to be called the Flagstones
Much of its humour derived from the Stone Age take on modern technology.
Notable examples include Fred's car, which was powered by foot, and the family's vacuum cleaner - a baby woolly mammoth who sucked up dirt with his trunk.
It was comedic touches like these that made Hanna-Barbera the standard bearers for animated television.
"They created a string of utterly memorable comedies," says Peter Lord, co-founder of Aardman Animations, who remembers watching the cartoons as a child.
"It was like a religious experience to see a show that was fast, noisy, modern and - as it seemed to me - incredibly sophisticated."
But no matter how popular Hanna-Barbera's cartoons were with audiences in the 1960s, they were despised by artists.
Yogi Bear's collar made him easier to animate
The duo had realised that, as cinema audiences dwindled, cartoons would find a natural home on television.
But they also knew that TV could never match the $45,000 budgets they had enjoyed when they created Tom and Jerry in the 1940s.
So they pioneered the technique of "planned animation" (also known as limited animation), which featured minimal movement and frequent recycling of backgrounds.
If you look at many of Hanna-Barbera's most popular characters - Fred Flintstone, Yogi Bear and Scooby Doo - you will see that they wear a necktie or have a prominent collar.
This meant that the body could remain static when the character was speaking, and the artists would only have to re-draw the character's face in each frame.
As a result of cost-cutting measures like these, the company reduced the number of separate drawings required for a seven-minute cartoon from 14,000 to nearly 2,000.
Although aficionados were offended at the loss of meticulously crafted, hand-drawn cartoons, Hanna and Barbera felt they had saved their industry.
"We went into limited animation because there was no money, absolutely no money," wrote Barbera in his autobiography, My Life in Toons.
"And because of what we were doing, the entire business came back to work again."
The technique certainly paid off for him, but few other studios could match the invention and wit of Barbera's characters.
According to legend, the animator would act out his cartoons in the studio, putting on accents and sketching new characters faster than his assistants could pin them up.
His death, at the age of 95, robs animation of one of its greatest pioneers.