A woman's sack back and petticoat of ivory silk, brocaded in a pattern of large floral motifs in shades of green, purple, maroon and pink. The sack back is open at the front, with robings to the waist and elbow length sleeves with double scalloped sleeve ruffles. The bodice is lined with linen, and the sleeves part lined with linen and white silk taffeta. The back has two double box pleats, with a waist seam extending from the pleats to the front openings. The sack back is made of 4 widths of silk and a partial panel on each side of the front. These panels are lined with white silk taffeta and the hem faced with the same.
The petticoat is made of 4 widths of silk and a pieced back panel.
The ensemble was probably made as a mantua and petticoat in the late 1730s, and re-made in the 1760s. The two centre back panels forming the box pleats have been pieced. Panels from the petticoat were probably used to construct the sack back. The sleeve ruffles were added at this time.
In the late 19th century, both were altered for fancy dress. The waist seam was probably reconfigured at this time, darts added to the fronts, and the front of the bodice linings removed. Loops and buttons were added to loop up the skirts. The back panel of the petticoat was pieced from flounces removed from the front. The waist was reconfigured and a waistband of linen added.
A calico stomacher with hooks & eyes was added to the sack back front for museum display