It is a sad day for children of a certain age, that the creator of Bagpuss and Ivor the Engine has died, aged 83.
With the help of artist Peter Firmin, Postgate created some of Britain's most popular children's television programmes: The Clangers, Ivor the Engine, Noggin the Nog and - perhaps their most famous - Bagpuss.
Bagpuss told stories of a magical cloth cat who slept in a shop window.
Each episode, Emily, the young girl who lived at the shop give the cat an object that she had found.
She would wake up Bagpuss who would then wake his friends - including Professor Yaffle, Gabriel the Toad and the mice from the Mouse Organ - who would identify and repair the item.
Oliver Postgate was born in North London in 1925. He was the grandson of the Labour MP George Lansbury and inherited many of his principles, risking prison as a conscientious objector during the Second World War. He was later to be active in the campaign against nuclear weapons, addressing public meetings and writing pamphlets.
He went into partnership with Peter Firmin, forming the production company Smallfilms.
It was just that; a two-man operation making short animated films from a makeshift studio in a disused cowshed in Kent.
They started in 1959 with Ivor the Engine, a series for ITV about a little Welsh steam engine who wanted to sing in a choir (it was remade in colour for the BBC in the 1970s).
They were simple stories and simple animations, no more than cardboard cut-outs. Firmin did the artwork, Postgate wrote the scripts, did the filming and many of the voices, in rather dodgy Welsh accents.
They produced two minutes of film a day, ten times as much as a conventional animation studio, with Postgate moving the cardboard pieces himself, and working his 16mm camera frame-by-frame with a home-made clicker.
It was a gentlemanly and rather innocent business, as Postgate later described.
"We would go to the BBC once a year, show them the films we'd made, and they would say, 'Yes, lovely, now what are you going to do next?'"
"We would tell them, and they would say, 'That sounds fine, we'll mark it in for eighteen months from now', and we would be given praise and encouragement and some money in advance, and we'd just go away and do it."
Their work took on a decidedly surreal edge with the Clangers, pink creatures with pointed noses who lived on a blue moon with a friendly soup dragon, and spoke in whistles.
Postgate and another actor did their voices with Swanee whistles, after Postgate had painstakingly written out every word of the script.
The original dialogue was virtually indecipherable, which didn't stop Postgate getting into trouble when a BBC executive correctly divined that for one clanger he'd written the line: "Oh sod it, the bloody thing won't open".
Oliver Postgate made his last film in 1987, complaining that children's television commissioners were no longer interested in what he had to offer.
With his story-telling skills, his love of found objects and mechanical improvisation, his funny voices and air of eccentricity, the man himself gave a good imitation of everyone's favourite uncle.
And his creations live on, at once surreal and comforting.