page, requiring the re-ruling of some pages. This change was evidently a departure from the original plan, and may have been caused by a shortage of the very fine vellum, as two different sorts are used, though the change does not coincide exactly with the change in the number of lines. Four passages are marked in the margin, which correspond to those used as readings in Masses for the Dead in the Roman lectionary of the mid-7th century. This seems to have been done hastily, as most left offset marks on the opposite pages from the book being closed before the ink was dry. This seems to indicate that the book was used at least once as the gospel book for a Mass for the Dead, perhaps on the occasion of Cuthbert's elevation in 698. In the example illustrated at left, the start of the reading at line 10 is marked with a cross, and de mortuorum ("for the dead") written beside. The reading ends on the next page, which is also marked. Binding The original tooled red goatskin binding is the earliest surviving intact Western binding, and the virtually unique survivor of decorated Insular leatherwork. The decoration of the front cover includes colour, and the main motif is raised, which is unique among the few surviving Early Medieval bindings. The panels of geometrical decoration with two-stranded interlace closely relate to Insular illuminated manuscripts, and can be compared to the carpet pages found in these. Elements of the design also relate to Anglo-Saxon metalwork in the case of the general origin of interlace in manuscripts, and Coptic and other East Mediterranean designs. The decoration of the covers includes three pigments filling lines engraved with a sharp pointed instrument, which now appear as two shades of yellow, one bright and the other pale, and a dark colour that now appears as blue-grey, but was recorded as blue in the earliest descriptions. The front cover includes all three colours, but the pale yellow is not used on the back cover. The pigments have been analysed for the first time, as one benefit of the purchase of the manuscript by the British Library, and identified by Raman spectroscopy as orpiment (yellow) and indigo (grey-blue). The balance of the designs on both covers is now affected by what appears to be the greater fading of the dark blue-grey pigment. The bookbinder Roger Powell speculated