PINK de Thierry (born Helena Scheerder, 1943) is a Dutch visual artist known for her meta-performance art projects, which included 100 days of living in a painting (At Home, 1984), 30 days of traveling in the US as a performance-art project in 1988, daily entering Arcadia for 60 days in Germany with Et in Arcadia Ego Sum in 1990–91 and leading the Royal Netherlands Army in constructing Checkpoint to Dutch Arcadia in 1994. Since 1995, she has created a series of works entitled Letters from Arcadia. PINK, began her career as a stage and film actress in Brussels under the name of Helen Pinck and or Helen Pink. She trained with the experimental Living Theatre when it presented Frankenstein in Brussels, Jerzy Grotowski's protégé André Desrameaux and Yoshi Oida at Peter Brook's International Centre for Theatre Research in Paris. During her time in Brussels PINK was influenced by designer-artist Raphaël Opstaele, poet Marcel van Maele, poet and visual artist Marcel Broodthaers (in whose vernissage of his Musée d'Art Moderne, Département les Aigles she participated at his home in Brussels in 1968) and architect Jef de Groote. In the autumn of 1968, the Laboratory of Theatrical Research at Louvain University commissioned André Desrameaux and PINK to create an experimental theatre piece. The resulting performance, Erektion, used text and vocalization by actors on a multi-level, wire-mesh stage over the audience. Erektion began a new art group, Mass Moving, which focused on art in public spaces. Participating in a performance artwork by James Lee Byars in the Wide White Space Gallery (Antwerp) in 1969 moved PINK toward the visual arts. Utrecht cultural deputy Jan Juffermans commissioned PINK, Opstaele and De Groote (who became Mass Moving) to create an outdoor event in the city center. The result, Motion (1969), was Mass Moving's first art intervention in an outdoor public space. A number of art-intervention projects on the scale of city life were created in public spaces in Europe, Africa and Japan.