1：it is deep blue solution,show acid and will be deteriorated with alkali

2：the color will be changed into black from blue due to the oxidation effective.

3：the writing is having gloss,and it will not be faded after irradiating by sun and water logging.
   

others：
1：Seal,avoid light,place in 5-25 degree
2：More than 144 types color special writing brush ink can be made,OEM provided.