在制作掐丝珐琅沙画过程中，需要用到一杯水来清洗画做，但是由于普通杯子容易倾倒，于是设计了这个上窄下宽的杯子。

In the process of making the enamel sand painting, it is necessary to use a cup of water to clean the painting, but since the ordinary cup is easy to pour, the design of this cup is narrow at the top and wide at the bottom.