on Saint Peter's mantle: Ave Maria grat...; on left wing, under the shell vault: ....NVS.DEI; on right wing, under shell vault: Q:TOLLI
Inheritance from the Estate of Peter A. B. Widener by gift through power of appointment of Joseph E. Widener, Elkins Park, Pennsylvania, after purchase by funds of the Estate, 1942.
The design, drawn in black or dark russet lines on the previously fired ground of white enamel, established the areas to be covered with layers of translucent enamel: blue, green, and purple. A mixture of white, blue, and red was applied for the flesh tones, producing a lilac tone after firing. Highlights were obtained by additions of thicker or thinner white, and anatomical modeling by scratching away and reworking. Under the white areas (the Virgin's wimple; Saint John's cloth), black enamel was laid and then scratched away with a needle (enlevage) to let thin black lines reappear. Enlevages could also bare the lilac ground of the flesh tone, as between the legs of Christ. Red, to render blood, was fired last, and, finally, gold stippling and hatching was fixed at a lower temperature in order to pick up details and accent the modeling. The three enameled plaques are set in a mercury- gilded brass frame, ornamented with alternating nails and sprays of foliage. The modern copper mounts are enclosed in a modern wooden case painted with foliage ornaments on a gilt background. All three panels have been restored, primarily in the lower portions. Localized deterioration (crizzling) exists in the mulberry drapery of the center panel.
 Peter E. Michaels, "Technical Observations on Early Painted Enamels of Limoges," JWalt 27-28 (1964-1965 ), 29-32, figs. 9-11. The use of bold cross-hatching for modeling is found in illuminations by Jean Bourdichon.
- Inventory of the Objects d'Art at Lynnewood Hall, Elkins Park, Pennsylvania, The Estate of the Late P.A.B. Widener. Philadelphia, 1935: 35, Raphael Room, as by Leonard Pénicaud.
- Works of Art from the Widener Collection. Foreword by David Finley and John Walker. National Gallery of Art, Washington, 1942: 10, as by Léonard (Nardon) Pénicaud.
- Wilson, Carolyn C. Renaissance Small Bronze Sculpture and Associated Decorative Arts at the National Gallery of Art. Washington, 1983: 215, no. 4, as by Jean I Pénicaud.