ECO-friendly.How to use the gaiwan:When using a bowl, the water should not be too full (cover the lid and the water will not overflow as standard). Use your fingers against the underside of the cup to ensure that the water does not burn your fingers. When pouring water, tilt the lid slightly and use your finger against the top of the lid to control the flow of water. Hoping it is helpful to you Craftsmanship:Celadon.The minerals are fired at 1300 degrees Celsius to form a surface glaze No harmful substances are produced during use,one of the healthy kitchen supplies. History:Celadon has thousands of years Longquan Celadon represents the pinnacle of porcelain making skills in the Song Dynasty,Longquan-Celadon surface has a layer of glass glaze.,Exquisite handiwork, delicate,Exported to multiple countries Please pay attention:The goods sold in our shop Decorative cracked products, is not recommended for long-term use for microwave ovensDecorative crack-free products, can be assured for microwave ovens and dishwasher.It is handmade by experienced artis in Longquan. It's a nice gift to your family or friends who loves tea or interested in Chinese Tea Culture.