There are no records to tell us how the carved cadavers were sculpted, nor who by. However, the canopy of a tomb of Giles de Bridport (d.1262) in Salisbury Cathedral shows an effigy being carved, and this gives us some clue. Although damaged, it clearly pictures 2 men with sculpting chisels; these are similar tools to those used today and the sculptor is recumbent (lying down).
An anonymous illustration in a French translation of De Claris Mulieribus (ca.1440) by Boccaccio shows a female sculptor. The effigy that she carved is being carved upright at an angle of 90° rather than laying down (recumbent). Details on a few British carved cadavers suggest that the upright carving method was used for their manufacture as they have a wedge shaped recess at one end, but it is likely we will never know. What is known though is that most of the British carved cadavers have a high level of anatomical accuracy which is quite unusual for the time as they pre-date Andreas Vesalius (d.1564), the father of modern human anatomy.
Carved cadavers are not only found in Britain but across much of Northern Europe in countries such as France, Germany, Ireland, and the Lowlands. Many of the continental carved cadavers are verminous; that is they have creepy-crawlies on them, or show a decomposing body. None of the British carved cadavers show a decomposing body, even those with an open chest or abdomen are carved with intact skin. One though, does have some creatures crawling on it.
This memorial in Tewkesbury Abbey has 2 snakes, a mouse, and a toad on it. The toad sites by the man’s left ear, and the mouse is on his belly-button. The mouse was an allegory for the soul and if it was painted red it showed his soul was good, but if it were black, then it showed him sinful. Snakes meant lust and disobedience whilst the toad was a symbol of uncleanness and the left side was associated with damnation.
British carved cadavers come in 2 main style, tiered and isolated. Tiered show the commemorated person sculpted in life as well as in death, such as this one below of Sir John Fitzalan (1408-1435) in Arundel Castle chapel
Isolated memorials just have the carved cadaver. This example of of Bishop Richard Fox (c1448-1528) at Winchester Cathedral.
A few memorials have an in-life image of the commemorated person as an engraved brass rather than a sculpture.