Hi Peter, here is a 4 character mark it is not listed in my books, I wonder if it could be a mid 20th century mark, can you read what is says, thank you for any information.
The correct characters are probably ????. This is a Japanese mark, related to the potter Inoue?Shunho ???? , the first name the last two characters, being the last two in the mark. The mark would probably read Heian Shunho. He is a contemporary potter it seems.
Thanks Peter, no wonder I could not find anything on it, I thought for sure it was Chinese, thanks again.