Advances and challenges of ceramic pigments for inkjet printing

In the last decades, the development of new ceramic pigments has been a very pursuit goal, mainly since the emergence of the inkjet technology applied to ceramic tiles. The digital decoration of industrial ceramics has contributed to a notable reduction of pigment consumption and an aesthetical decoration improvement, which makes more flexible the production processes, enhancing the reproducibility and cost savings. The nanopigment requirements of the inkjet technology demand submicronic particle size, ink rheology, stability, drop resolution, etc. Although the up-down procedure by micromilling contributed firstly to the particle size reduction of existing pigments, novel approaches are developed to obtain directly high-quality particles of suitable size with the aim of providing a higher optical efficiency. Thus, in this work, a comprehensive review about the existing crystalline structures, novel compositions, and synthesis methods as well as new coloring mechanisms is addressed, giving an overview of all these advances while considering the four-color process required for inkjet technology. The inkjet technology has the challenge of evolving towards a sustainable technology by eliminating the use of critical raw materials, removing the use of synthesis aid fluxes, and reducing the energy consumption, to approximate to a circular economy which is predominant in this sector.