The contrast between the colourful and vibrant butterflies and the monochrome and morose skulls of this series could not be greater. However, both series were conceived together at the same time. The skulls are, as it were, the other side of the coin to the butterflies. Just as the butterflies were all different species, by presenting multiple skulls, and on such a grand scale, Hirst also brings out the individual character of each. As a symbol and reminder of the transience of life, the skull has been a firmly established motif in art since the Vanitas still-lifes of the seventeenth century. Hirst lets his skulls emerge eerily from their black surroundings to confront us with unnerving immediacy. The title of the series, a translation of the Latin epitaph ‘Quod tu es, ego fui, quod ego sum, tu eris’, leaves little doubt as to its meaning and purpose. The Jesuits recommended the use of a skull as an aid in the contemplation of death as part of the spiritual exercises formulated by the founder of the order, Ignatius of Loyola. Here, it is as if Hirst has the skulls speak to us directly, prompting a reflection of our own mortality.
The skull prints were made using the same process as for the butterflies. However, as these are monochrome, two plates were sufficient to print them, with the gravure plate doubling up as an aquatint plate for the black background.