Determining a characteristic of a substrate

A print apparatus, comprising:

• a laser source to direct laser light onto a printable medium;
• a diffuse light source to direct diffuse light onto the printable medium;
• an image capture device to detect i) laser light reflected from the printable medium and ii) diffuse light reflected from the printable medium;
• and
• processing circuitry to:
• determine, from the reflected laser light, a first parameter relating to the printable medium;
• determine, from the reflected diffuse light, a color relating to the printable medium;
• and
• determine a characteristic of the printable medium based on the color and the first parameter relating to the printable medium.

A non-transitory machine-readable medium storing instructions which, when executed by a processor, cause the processor to:

• obtain first image data relating to a reflection of laser light from a printable substrate;
• obtain second image data relating to a reflection of diffuse light from the printable substrate;
• determine from the first image data, a first parameter relating to the printable substrate;
• determine from the second image data, a second parameter relating to the printable substrate;
• and
• determine, using the first and second parameters, a characteristic of the printable substrate using a model generated from a machine learning process.