Tea Leaf Waste: Pigment Production Process and Application in Painting

Abstract

This paper explores how to transform tea dregs discarded in milk tea shops into watercolor pigments, focusing on the process and methods of pigment design, aiming to provide new ideas for sustainable material design. The study uses Chinese black tea, green tea, Thai black tea, and green tea as raw materials, and combines different chemical substances (such as acid, alkali, and mordant) for color regulation. During the experiment, the tea dregs were first boiled to extract the pigment solution, and then mordants (such as alum, citric acid, and sodium bicarbonate) were added to adjust the color tone. Subsequently, the pigment powder was precipitated, dried, and ground to form a pigment powder, which was combined with watercolor binders such as gum arabic to form watercolor pigments that can be used for painting. The results show that different types of tea dregs can produce rich color changes under specific chemical treatments, showing a variety of tones from warm brown to dark gray-blue. These pigments were used in painting experiments. The works revolve around the theme of "cycle and continuity" and emphasize the sustainable relationship between man and nature. The study not only verifies the feasibility of tea dregs pigments in artistic creation, but also provides new possibilities for the application of environmentally friendly materials in painting.