Complex sentence: Hayter is noted for his work in the development of viscosity printing--a process that exploits varying viscosities of oil-based inks to lay three or more colours on a single intaglio plate.
Split into simpler sentences: Hayter is noted for his work in the development of'viscosity printing'. This process exploits varying viscosities of oil-based inks to lay three or more colours on a single intaglio plate.