Fountain solution thickness measurement using optical properties of solidified fountain solution in a lithography printing system

A method to measure fountain solution thickness for variable data lithography printing comprising:

• using an engineered surface with an opacity that varies as a function of fountain solution thickness;
• using an emissive light source to pass a light along a path from the source through the engineered surface;
• receiving light passing through the engineered surface at the light detector;
• generating a signal proportional to the opacity level of the engineered surface from the light impinging on the light detector;
• and
• determining the thickness of the fountain solution on the engineered surface from the opacity level, the method further comprising cooling the engineered surface to phase change the fountain solution to a solid.

An ink-based digital printing system useful for ink printing, comprising:

• a processor;
• and
• a storage device coupled to the processor, wherein the storage device comprises instructions which, when executed by the processor, cause the processor to control fountain solution deposition process and maintain fountain solution at a set thickness for variable data lithography printing by:
• using an engineered surface with an opacity that varies as a function of fountain solution thickness;
• using an emissive light source to pass a light along a path from the source through the engineered surface;
• receiving light passing through the engineered surface at a light detector;
• generating a signal proportional to the opacity level of the engineered surface from the light impinging on the light detector;
• determining the thickness of the fountain solution on the engineered surface from the opacity level;
• and
• controlling the fountain solution deposition process based on the determined thickness of the fountain solution, the processor further performing cooling the engineered surface to phase change the fountain solution to a solid.