In Australia, the only cheese you could buy in the supermarket in the 1970s was Kraft in the little blue packets sold in the dry goods section.

To buy “real” cheese you had to go to a dairy, or go to the city centre and buy cheese cut off the block and wrapped in greaseproof paper from a contintental delicatessan.

Polyethylene film was not available.

So when it came out and you could buy real cheese in film from the supermarket, Kraft responded by bringing out "more convenient " Kraft Singles, which you didn’t have to laboriously (?) cut from the block.

Its salted curds like cheese, but its not matured. Instead mineral salts are added which absorb the water, the same sort of stuff used in corned beef, bacon and ham.

The colouring is artificial. Its naturally a light grey colour.