The first part of the article recounts the history of the painting, describes its condition, and discusses the controversy about its date. The second part summarizes the results of the technical examination and compares the materials and techniques to other Rembrandt paintings examined at the National Gallery in London. In general, Miss Plesters has found that his panel paintings have a single whitish chalk/glue ground, whereas his paintings on fabric usually have two colored ground layers. She discusses the rare evidence of any underdrawing and describes Rembrandt's method of first applying thick light paint with a palette knife or with his fingers, leaving the areas of design that will be dark uncovered, and then applying more colorful and darker paint over this underlayer. His palette tended to be limited in his early work but of greater variety in his later paintings. In the case of the Stoffels portrait, Rembrandt used what appears to be walnut oil for the medium, perhaps because it was thought to yellow less than linseed oil. Miss Plesters lists the pigments found in the portrait, mentions the rare occurrence of actual blue pigments in Rembrandt's work in general and says that ultramarine has never, so far as the present writer is aware, been identified in a painting by Rembrandt. Finally, she notes how difficult it is, given Rembrandt's style of painting, to determine when he has left a painting unfinished -- a question which has been asked of the Hendrickje Stoffels portrait. -- AATA