A chemical coloring method for stainless steel, which does not use pigments or dyes, involves immersing stainless steel in a heated concentrated chromium sulfuric acid solution. Its characteristic is excellent resistance to food-grade corrosion. The inks used in this processing method must have strong acid resistance and typically employ UV-curable inks with specific properties that are compatible with the treatment process.

There are roughly two main methods for processing the appearance of stainless steel. One involves enhancing the stainless steel’s appearance through treatment to give it a glossy surface, often creating artistic patterns using variations in gloss. The other method involves adding colors to the pattern design. Typical examples of these methods employing screen printing include etching and color spraying processes.