Hand-made artist signed "The Folger Company" and has a unique K above it. Excellent condition and glazed inside and out besides the very base. Mug states "God Give You Joy" on the outside in blue. Measurements can be seen in photos. I tried to research this and could only come up with The Folger Shakespeare Library which was started by Henry Folger in 1889 and posseses some amazing literature. There's a huge amount of information about this out there and is quite fascinating. However, I can not verify 100% that this is related to that. It is all I could find when researching about it. If you have any questions, please do not hesitate to contact me.