The ESE system, invented and patented by illy in 1972, has set a fashion worldwide, so much so that it has become a standard. Its servings contain 7 grams of pre-measured ground coffee tamped between two layers of food filter paper, and they can be used on all ESE compatible machines. ESE has other advantages too: it is cheap, convenient and environmentally-friendly, because all that is left once the servings have been used are the paper and the coffee grounds. According to Illy its caffeine content is less than 0.05%.