传统的印章用料主要有金、银、铜、象牙、石等，其中铜印章起源于东周，年代久远，而且使用范围广、数量大，被历代统治者作为官印或私印。铜印章被广泛使用的原因，是铜的冶炼铸造得到发展，又较之金银来源丰富，而且在铜中掺入一定比例的锡、铅、锌则更适宜镌刻。印章作为艺术品，其价值一般表现在两个方面，一是其外形设计，也就是印钮的设计、铸造技艺及后期更高层次的深加工技艺；二是印面文字的书法和镌刻艺术。
The traditional materials used for seals mainly include gold, silver, copper, ivory, stone, etc. Among them, copper seals originated from the Eastern Zhou Dynasty, have a long history, and are widely used and in large quantities. They have been used as official or private seals by rulers of various dynasties. The reason why copper seals are widely used is due to the development of copper smelting and casting, as well as the abundance of gold and silver sources. Moreover, adding a certain proportion of tin, lead, and zinc to copper is more suitable for engraving. As a work of art, the value of seals is generally reflected in two aspects: firstly, their appearance design, which includes the design of buttons, casting techniques, and higher-level deep processing techniques in later stages; The second is the calligraphy and engraving art of printed characters.
铜印材较之其他印材，如石、木、牛角、象牙、有机玻璃等，有坚久耐用、传世性强、艺术表现形式丰富、适宜加工的优势。铜印颜色庄重，它可以比上述印材表现更细致、镂空等，配合错金、错银、鎏金、錾制等表面深加工技术，铜印章可以高层次地表现永恒、持久、庄重、高贵的气派。
Compared to other printing materials such as stone, wood, ox horn, ivory, and organic glass, copper printing materials have the advantages of durability, strong inheritance, rich artistic expression forms, and suitability for processing. The color of the copper seal is solemn, and it can be more detailed and hollow than the above-mentioned printing materials. Combined with surface deep processing techniques such as gold, silver, gilding, and chiseling, the copper seal can express an eternal, lasting, solemn, and noble atmosphere at a high level.
第一印为龙纹印章，材质是精铜，传世古印，是皇帝赏赐的用章，龙纹在钮背上栩栩如生盘在印章之上，底部印文“王山时印”。第二印为青蛙印章，材质为精铜，传世古印，是一枚文人用章，青蛙四条腿屹立，神态生动，双眼圆睁，嘴微张，底部印文“郑统之印”。第三印为虎印，材质为精铜，传世古印，是一枚将军用章，虎栩栩如生，凶猛之态。这三印极为难得，有极高的收藏价值。
The first seal is a dragon pattern seal, made of refined copper and passed down from ancient times. It is a seal bestowed by the emperor. The dragon pattern is vividly coiled on the back of the button on top of the seal, and the bottom is printed with the words "Wang Shan Shi Yin". The second seal is a frog seal, made of refined copper and passed down from ancient times. It is a seal used by literati. The frog stands tall on four legs, with a vivid expression, eyes wide open, mouth slightly open, and the bottom seal reads "Zheng Tongzhi Seal". The third seal is the Tiger Seal, made of refined copper and passed down from ancient times. It is a seal used by generals, and the tiger is lifelike and fierce. These three seals are extremely rare and have high collection value.
