Although barium sulfate is almost completely inert, zinc sulfide degrades upon exposure to UV light, leading to darkening of the pigment. The severity of this UV reaction is dependent on a combination of two factors; how much zinc sulfide makes up the pigments formulation, and its total accumulated UV exposure. Depending on these factors the pigment itself can vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant may be used, such as a small amount of cobalt salts, which would be added to the formulation. This process creates cobalt-doped zinc sulfide. The cobalt salts help to stabilize zinc sulfide so it will not have as severe a reaction to UV exposure.

It is expected that the implementation of rutile titanium dioxide market manufacturers will be stable this week, the new single quotation of the production link will be firm, the supply of low-cost goods will be reduced, and the reference range of the overall market transaction will rise slightly. It is expected that the market transaction reference is 15200-16200 yuan/ton, and the weekly average price may refer to 15600 yuan/ton. In addition, considering the difference of orders received by different manufacturers, some manufacturers may still have 300-500 yuan/ton of negotiation room. On the demand side, most buyers still have inventory to use, so the current new batch transaction intention is not strong; On the supply side, some producers are expected to increase the load next week, so the industry time output may be slightly increased. On the whole, it is expected that the overall trading range will rise slightly next week, but most producers will adjust the real single negotiation range according to their own orders, and the new single stable price of mainstream producers.