If you find any vintage passe partout tape on your travels, how do you date it? Well, if it's Butterfly Brand, made by the Samuel Jones company, there is an easy way: passe partout manufactured in the 1950s was designated "MADE IN ENGLAND". From the 1960s onwards, it was designated "MADE IN GREAT BRITAIN". The "MADE IN ENGLAND" version has the product details printed on a circle of paper inside the packaging; the "MADE IN GREAT BRITAIN" version has the product details printed on the cellophane wrapping.
In answer to a query, the modern Lion Brand tape listed as "passe partout" is not the paper tape we refer to in this blog.