Yellow striped Cornish Ware was made in England by T.G. Green beginning in 1960, using the same molds as they'd used in the 1930's for their popular blue striped pieces. The line was redesigned later in the 60's and after that the target backstamp replaced the green or black shield marks. So the jam jar can be dated accurately as made between 1960 and 1967. It measures 4-3/8 inches tall and 3-1/4 inches in diameter and is in perfect condition.
Vintage Yellow Cornish Ware Jam Jar