The test card usually has a set of line-up patterns, enabling televisions to be adjusted to show the picture correctly. (Compare with SMPTE color bars). They would also typically be broadcast to a background of specially composed music, to avoid having to pay licencing fees for existing compositions. There is now a cult following for test-card music.
The most famous British test card is Test Card F and its successor Test Card J, used on the BBC and ITV from the beginning of colour broadcasts in the late 1960s. See separate articles for full details.
Formerly a common sight, test cards are now only rarely seen. Two things have led to the demise of the test card: