Trimethylsiloxysilicate is a high-molecular-weight, resinous silicone polymer composed of branched siloxane units terminated with trimethylsilyl groups. It forms a durable, flexible, and water-resistant film on skin, hair, and surfaces. Known for its excellent adhesion and transfer resistance, it enhances the wear, rub-off resistance, and longevity of formulations. It is particularly effective in color cosmetics, sunscreens, and other applications requiring long-lasting performance under sweat, humidity, or mechanical stress.