Basically, a design was drawn on an écru batiste or linen ground and then a filoselle thread of “a bright and contrasting shade” (p. 426) was used for embroidery. This is an important point, as many forms of cutwork use a thread in the same colour as the ground material (as in Roman work [écru] and broderie Anglaise [white]).
Closely worked buttonhole stitches were used to outline the desired pattern, making sure that the outer edges of the buttonhole stitches were always on the outside of the pattern. The areas of batiste/linen not enclosed by the lines of the buttonhole were cut away (hence its designation as cut work). The areas inside the buttonhole stitches was sometimes left plain, or filled in with decorative stitches of some kind. Often the batiste/linen was lined with a coloured silk cloth, so that the design would became more prominent.
Source: CAULFEILD, Sophia Frances Anne and Blanche C. SAWARD (1882), The Dictionary of Needlework: An Encyclopaedia of Artistic, Plain and Fancy Needlework, London: L. Upcott Gill, p. 426.
GVE