The nucleus of the collection of NLW Microfilms is microfilm of manuscripts in Welsh and of Welsh interest in other major libraries: the British Library; Jesus College and the Bodleian Library, Oxford; Cambridge University libraries; the Hereford Cathedral manuscripts; Welsh material from the Public Record Office, now the TNA; the Bangor MSS; and some from other record offices in the United Kingdom, and overseas libraries and archive repositories. The Cardiff manuscripts (over 4,000 in number) are listed in a separate catalogue (Cardiff MSS on Microfilm). Commercially produced microfilms and microfiche are also not included in this catalogue.