From Laughing Moon Mercantile:
Ladies' Regency Wrapping Front Spencer with 4 Collar and 3 Back Variations c. 1798-1809 All Views and Spencer jackets. They all have a wrapping front. View A has a ruffled collar. View B has a long falling collar and a ruffled back. View C has a tall falling collar and pleats at the center back. You can also opt to omit the falling part of the collar and have just a standing collar. There is also an option for a lower neckline with no collar. All Views have a two piece sleeve with attached cuff. All Bodices have four total darts. The darts can be converted to gathers.
Fabric: wool, cotton, linen, or silk View C is best made with wool because of the construction of the high collar. Printed or figured, striped or plain, embroidered, spangled, or all over motifs. Interfacing: View B Hair Canvas. View C Linen collar interfacing. Lining: unbleached muslin or silk Habotai (China Silk). Notions: 2 yards cotton or linen 3/8" tape.