The back of the bag has a description about the Royal Stewart Tartan:
“Originally a Royal tart of the Royal House of Stewart and the personal tartan of the reigning British monarch. Theoretically it cannot be warn without the express permission of the monarch but it has become so popular and so widely worn that is is now regarded as the universal tartan.
In the late 1970s the Royal Stewart tartan was adopted by the Punk movement. Today is it best-known and most popular tartan ever woven and appears on a wide range of products.”
The back of the bag also depicts the details of the pleats of what would be the back of the kilt.