Gwen Manthey, a private art conservator in Washington, D.C., requires clients to sign contracts acknowledging that treatment costs may exceed artwork values. In contrast to past art schools' emphasis on materials and techniques for longevity, many modern art programs focus on artistic expression and theory. Paul Himmelstein, a partner at Appelbaum & Himmelstein in New York City, notes that contemporary artists have become increasingly experimental, leading to concerns about the long-term preservation of their work.