You should shade the object where the light does not hit it and make it the lightest where the light hits it
Make it the lightest of all the rest. Or if it's a dark painting, lit by candle light, then it would be the most normal colouring with a yellow-ish tint.
To show a surface that reflects the most light in a painting, an artist should use lighter colors and highlights, apply the chiaroscuro technique for contrast, consider reflections and texture, and carefully place shadows. These techniques create the illusion of a reflective surface and enhance visual interest. By blending these methods, artists can depict surfaces like shiny hair or glossy materials effectively.
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