A woman's sack back and panel from the petticoat of blue ribbed silk, embroidered to shape in a tree-of-life pattern in shades of blue and white. The sack back is open at the front with robings to the waist and elbow-length sleeves. The bodice has a half-stomacher each side of the front. The bodice back and sleeves are lined with blue striped linen; the bodice fronts with plain linen. The back of the bodice lining is open down the centre, with 17 worked eyelets either side and narrow linen-tape lacing. There are two double box pleats at the back, stitched at the back neck. The sack back is made of 2 widths of silk with 2 partial panels and a triangular gore either side of the front. A waist seam runs from the front openings to the bodice side back seams. The skirts are flat pleated into the waist seam along the front, with pocket openings in the side seams. The right front of the skirt is faced with blue silk taffeta (this has been removed on the left front). The hem is faced with a deep band of linen. The skirts robings, wide at the hem and narrowing to the waist, are embroidered.
All that remains of the petticoat is the central panel, one width of silk with the tree-of-life embroidery arranged in a triangular shape.
The ensemble was probably made as a sack back and petticoat in the 1750s. In the 1780s, the sack back was updated in style. A waistseam was probably added, the skirts reconfigured, and sleeve ruffles removed. The half-stomachers were added at this time and the bodice fronts relined. The back lacing was reconfigured and more eyelets worked.
The ensemble was altered for fancy dress in the late 19th century. Hooks and eyes were added to the bodice stomacher fronts and machine-lace ruffles to the sleeves. The petticoat may have been unpicked at this point.
The petticoat was gathered onto a cotton band after acquisition for Museum display.