An article in Harper’s Monthly Magazine for June to November 1892 describes the process of making a mould for a mask. Here the subject – ‘Mr A’ – is alive, but the technique would be more or less the same with a corpse:
The hair and the face being annointed with a little pure scented oil, the plaster was laid carefully upon the nose, mouth, eyes, and forehead in such a way as to avoid disturbing the features; and this being set, the head was pressed into a flat dish containing plaster, where it continued to recline as on a pillow. The plaster was then applied to the parts of the head still uncovered, and soon afterwards the mould was hard enough to be removed in three pieces, one of which, covering the occiput [the back of the skull], was bound anteriorly by a vertical section immediately behind the ears, and the other two, which covered the rest of the head, were divided from each other by pulling up a strong silken thread previously so disposed upon the face on one side of the nose.
