Ten-fold printing is also called printing, which was not available in Qin and Han Dynasties. It has been used in official seals since the Tang and Song Dynasties. The ten-fold seal script is based on Xiao seal script. The strokes are repeatedly folded, circled and folded, and the vertical and horizontal directions are stippled to fill the blank parts and achieve unity. "Smooth and full" is the biggest feature of the ten-fold seal script method. The number of folds, the number of folds of each word, depends on the complexity of the strokes, including 50%, 60%, 70%, 80%, 90% and 10%. Call it a 10% discount, "Nine has a number of tails and many words", and describe how many discounts it has. Ten-fold seal script prevailed in Tang, Song, Yuan and Ming dynasties, and has continued to this day. When this "Nine Reprints" was used in Qian Wen, among thousands of ancient coins, "Song Emperor Bao Tong" was only an isolated case, so it was regarded as a rare treasure by collectors in past dynasties. As for the casting background of Huang, Song and Jiu reprints, numerologists generally think that this coin is "sample money" or "furnace money" and should not be a real currency.