This series is made up of digital images in greyscale of 6500+ plaster and rubber moulds and impressions of seals relating to a wide variety of documents held across The National Archives collections and across all chronological periods.
The oldest moulds date from the late nineteenth century. From then until around the mid-1960s the moulds were made from Plaster of Paris sifted through fine gauze. This material was then superseded by silicone rubber, which continued to be used until the late 1990s, when the practices of moulding and casting ceased.
Seal moulds can be extremely valuable, particularly in cases where surviving seals have suffered damage since moulding or where the original seal has now been lost (in some cases the mould might be the only surviving evidence of an impression or of a legend in full), although in a number of examples the separation of seal, and therefore mould, from parent document means little can be deduced of ownership or date.
The digital images have been scanned at 800dpi (although presented as compressed JPEGs), to provide high resolution, research-quality surrogates. Care has been taken when cataloguing the digital images to examine the original seals in cases where identification is not obvious from the mould and its associated documentation.
In terms of access, catalogue descriptions of the digital images include the following content:
- seal owner(s), both individuals and corporate bodies;
- the reference of the parent document from which the seal mould was taken (from which researchers can link through to that document to order a copy or to be produced in the Map and Large Document Reading Room at The National Archives;
- the seal's colour;
- the seal's dimensions.
Each image has also been assigned a broad category relating to the type of seal and / or sigillant, and the images can be searched by name and category; for example:
- England and Wales: Ecclesiastical (archbishops, bishops, diocesan officials);
- England and Wales: Monastic (heads of religious houses and institutional seals);
- England and Wales: Royal: Great Seal;
- Personal: Equestrian;
- Personal: Non-armorial.
The overall date range of the seal moulds and original seals are: Moulds, 1880-1995; Seals, 1136-1953.