this yellow toner cartridge uses ea-hg toner which is a xerox patented technology. emulsion aggregation toner is a chemical toner using resin pigment and wax particles that are formed in water. toner particles are smaller in diameter and uniform in shape in comparison to conventional toners. this results in improved print clarity and sharper detail. ea-hg toner used in this cartridge is high grade toner which makes further improvements to standard ea toner performance.