Color mapping with phosphorescent materials

A method comprising:

• receiving input data;
• and
• determining, using at least one processor, at least one mapping from an input data color space to a print apparatus color space, wherein each color in the print apparatus color space is associated with at least one print material of a print apparatus, and at least one print material or combination of print materials of the print apparatus is associated with an illuminated output color and a phosphorescent output color;
• and
• wherein determining the mapping comprises determining a mapping based on the associated illuminated output color and phosphorescent output color.

A method, comprising:

• printing a set of color samples, wherein each color sample is printed using one or a combination of print materials, and wherein at least one of the print materials comprises phosphorescent material;
• exciting the phosphorescent material in the color samples;
• imaging radiation emitted from the color samples in a low light environment;
• and
• characterising, using at least one processor, a low light color gamut based on the colors of the emitted radiation.