Hernmarck is known for her monumental tapestries, found in numerous corporate and museum collections, including the Metropolitan Museum of Art, Museum of Modern Art, Museum of Arts and Design, the Detroit Art Institute, Time-Warner, Kellogg, Pitney Bowes and Newsday, which are based on photographs, rephotographed collages and her own watercolors. Using a technique of her own invention, she is able to conjure details from our visual world, such as sunlight on waters and sails swelling in the wind.