Yet when young Tom applies them to a sheet of paper in Mrs Palmer’s art class the inevitable result is a spiral of watery brown goo that resembles nothing more than diarrhoea being sucked in to the path of a passing tornado.

Tom works with the fervour of a true artist and the titles given to his muddy output are various. One goo was simply entitled “Tractor”, another depicted “What We Did On Our Summer Holidays” and a third, somewhat alarmingly, was called “Tom’s Daddy”. To be honest I have had some doubts about the careworn photo that adorns this column, but at least it does have the virtue of being easily distinguishable from a Massey Ferguson tractor or sandcastles on a Cornish beach.

Tom, however, is undaunted by the public’s scepticism. He can see beyond the goo to a greater truth and for that I respect his artistic integrity. What I am less happy about is the way Mrs Palmer insists on sending my son’s art home with him. If these pictures were simply posted I would not mind too much, but Mrs P believes in regular handing-over ceremonies down at the school gate.

How I blanch at the sight of youngsters tottering out of school with their large damp flags of paper. More chilling still are those five dread words “I done a picture, Daddy”. It is for moments like this that the euphemism “Lovely, darling” was coined.

But for a father it is not so easy. Any man who uses words such as “lovely” and “darling” around our way is asking for trouble, so when Tom announces “I done a picture Daddy”, I keep it positive but noncommittal. “So you have,” I reply, or “My that’s very brown, Tom!” But Tom is grown up. He no longer considers Postman Pat the height of sophisticated comedy. How long before he asks for a more detailed critique. “Do you like my picture Daddy?” It is the most difficult question a man ever has to answer.

Tom may have artistic integrity but how do I retain mine at the school gate? That’s what I want to know, Mrs Palmer.