It showed two small figures with little beards and bald pates. The caption had Jimmy saying to his fellow teacher at Glasgow School of Art, David Donaldson: “I don’t know why people mistake me for you. I don’t look like either of us and neither do you.”

There was certainly a substance in the charge that Jimmy and David resembled each other. When I first met them at the Renfrew Street art school as a young man, I got them confused myself. They even dressed in similar corduroy trousers and blue shirts.

But there the appearance ended. Donaldson was a wonderful technician but Jimmy, it seemed to me, had the greater depth as a painter, for he was very much a painterly artist. He was very active in his painting, slashing away, inscribing and scratching, always looking for another layer, another surface. In this he was very European, and like the Scottish Colourists. I have one of his paintings, a lovely thing. It shows the gasfields at Grangemouth at night. The vividness of the colour is spectacular and I love this little masterpiece. But it is not for me to say anything about his work except that I loved it.

He was an exceptional teacher. Over the years that I have encountered the many catalogue notes for shows by so many Scottish painters, time after time you discover yet another artist who cites Jimmy Robertson as a major influence, more than any other artist teacher in the past near 50 years.

What made Jimmy such a well-loved figure wherever he went was that he was one of the chirpiest chaps you could meet. He liked and created conviviality. It is hard to imagine the art club without the familiar imp sitting on the arm of his battered armchair. And he was impish, for he had a certain gallusness to both his art and his personality which never quite masked his seriousness as an artist. It is just that he always seemed both serious and cheerful. And it is not often you get that in anybody at all.