The lotus shaped warm bowl from the Ru kiln of the Northern Song Dynasty was used to produce porcelain. The original vessel should be paired with a holding pot and was commonly used for warming wine during the late Tang and Song dynasties. Currently housed in the National Palace Museum in Taipei. Ru kiln was once used in the palace, but due to the method of covering and firing, the mouth had defects. Therefore, there was a move to "order Ruzhou to burn celadon in the palace". The selection of Ru kiln and the use of fully glazed support should be one of the reasons.

This paper hammer bottle has a total height of 22.4 centimeters, a diameter of 4.4 centimeters, and a bottom diameter of 8.6 centimeters. Round mouth slightly luxurious, with embedded copper buckle, slender neck, sloping shoulders, cylindrical belly, flat bottom without feet. The entire vessel is coated with sky blue glaze, and there are five small burn marks on the outsole. A circle of glaze has been removed from the bottom and coated with brown juice, revealing a yellowish color in the center, which may be caused by a cushion mark. The bottom of the paper hammer bottle is engraved with a poem by Emperor Qianlong titled 'Ru Kiln Pink Green Offering Hua Paper Hammer Bottle'. This cultural relic was produced in the second half of the 11th century to the early 12th century of the Northern Song Dynasty and is classified as a national treasure. It is currently housed in the National Palace Museum in Taipei.