Provided herein are methods of obtaining good photocured-ink adhesion to low surface energy materials. The methods have greatly improved adhesion of photocured ink on low surface energy materials, including those that are subjected to high humidity or wet environments. The methods take into account the glass transition temperature (Tg) of the materials and the onset for the glass transition temperature, including ink applied to an exposed surface of the material at an elevated temperature that is close to the Tg of the material. The ink is allowed to sit briefly or soak, such as for more than 1 second, before the ink is cured. The ink may be photocured. Furthermore, the methods do not require solvents or surface treatment, including plasma or corona treatments, to obtain good ink adhesion.