Susan Hartnett’s work is characterized by two distinct, but related modes of expression: the dynamic charcoal drawings of field, marsh and dune grasses; and the large-scale, richly colored pastels on painted paper. The charcoal drawings evoke a range of metaphors and associations that mirror human experience, references at once private and universal in the perennial cycle of life, death and renewal.
“Hartnett has a keen discernment for the properties of charcoal – its weight, density and pliability – and the manner in which she sets down her line is deftly unadorned.”  “Allowing charcoal to stutter and flow, thicken and thin, smudge and smear – she makes it look easy. Her drawings, made with the precision of a botanist, have the economy of a haiku.” 
"[In the pastels], recollections of walks in wood and field and seaside,…movements and counter movements are abetted by the nature of the materials. Pastel is the most pure of all colored media, so that color reaches its highest pitch and saturation. A sweep of the arm, with varying pressure, can bring the truest intonation and even heighten perception. A color can be read as a linear direction, an accent, a solid object, a level in the complex spaces of nature. As we sometimes find in Kandinsky’s paintings, there are various vortices from which strokes energetically suggest centrifugal movements." 
Susan Hartnett’s work is informed by both Asian and western aesthetic traditions – from Zen and Taoist philosophers and painters to such modern and contemporary artists as Degas, Matisse, Pollock and de Kooning. “What de Kooning and Ms. Hartnett share is a deep-seated commitment to the natural world, an inclination to settle imagery within the parameters of the page, and a love of mark-making as a primal gesture of individuality.”  Sources of inspiration aside, Hartnett demonstrates a singular and independent awareness of the power of art to illuminate ordinary phenomena. She successfully provides for the opposing claims of science and art, rational thought and mysticism, the lush and the austere, the awkward and the classically balanced, the literal and the abstract. “Like a diarist, she records the living universe, "this season, this day, this hour, this wind velocity, this tidal breeze, this kind of grass, …this kind of snow, this silence, this sound in the grass, this pitch of the wind." 
 Naves, Mario. “Even Her Smudges Have Humility,” The New York Observer, November 27, 2000, p. 17.
 Idem. “Making Her Mark,” The New York Observer, August 4, 2003, p. 16.
 Ashton, Dore. “Susan Hartnett,” catalogue essay, Susan Hartnett: Recent Work. New York: Danese, 2000, p. 7.
 Naves. “Making Her Mark,” 2003, p. 16.
 Ashton. “Susan Hartnett,” 2000, p. 5.