In our Letter, two kinds of handwriting traces, colored and colorless, are studied by means of reflectance transformation imaging. The illumination direction and rendering mode can be changed alternatively to obtain two-dimensional and three-dimensional details of the traces that are not recognized easily by naked eyes. Furthermore, an objective evaluation method without reference is applied to evaluate the reconstructed images, which provides a basis for setting the illumination direction and rendering mode. Therefore, the handwriting trace information including the written content, the writing features, and the stroke order features can be obtained objectively and accurately.