According to the ancient literature, adding talc into painting and calligraphy (P&C) mounting paste was adopted seasonally to help preserve the paste and to improve its performance. Some tests were done to exam the role of talc in paste. It was found that adding talc can affect the viscosity and acidity of the paste: within a certain concentration range, the viscosity and acidity of the paste increased, while out of this range both viscosity and acidity of the paste decreased. This study also showed that adding talc has no effect of inhibiting mold. Further research is needed to determine the influence of talc and other additives on P&C mounting paste performance.