The piety of individuals often led them to expend large sums in the preparation of their offerings to the Church; the finest and best parchment which could be procured being used for manuscripts. When black ink was used in liturgical writings, the title-page and heads of the chapters were written in _red ink_; whence comes the term Rubric. Green, blue, and yellow inks were used, sometimes for words, but chiefly for ornamental capital letters; the writers and miniature-painters exercising their own taste and judgment in the decoration, and heightening its effect with gold and the most expensive colours, such as azure and the purest cinnabar or vermilion. The greater part of these works were intrusted to monks and their clerks, who were exhorted, by the rules of their order, to learn writing, and to persevere in the work of copying manuscripts, as being one most acceptable to God; those who could not write being recommended to learn to bind books. Alcuin entreats all to employ themselves in copying books, saying, "It is a most meritorious work, more useful to the health than working in the fields, which profits only a man's body, whilst the labour of a copyist profits his soul."[45] Home production could, however, by no means suffice to multiply books, and especially religious books, with sufficient rapidity to satisfy the eager demand for them. Long journeys appear to have been taken to foreign countries, by learned ecclesiastics, for scarcely any other purpose than the collection of manuscripts; while quantities were imported into England from abroad. Thus Bede tells us, that Wilfrid, bishop of Wearmouth and Jarrow, and Acca, Wilfrid's successor, collected many books abroad for their libraries, at the end of the seventh century. Thus Theodore of Tarsus brought back an extensive library of Grecian and Roman authors, on his return to Canterbury, in 668, from a mission to Rome; and thus, as we are told by Mr. Maitland,[46] when "Aldhelm, who became Bishop of Schireburn in the year 705, went to Canterbury, to be consecrated by his old friend and companion Berthwold (pariter literis studuerant, pariterque viam religionis triverant), the archbishop kept him there many days, taking counsel with him about the affairs of his diocese. Hearing of the arrival of the ships at Dover during this time, he went there to inspect their unloading, and to see if they had brought anything in his way (_si quid forte commodum ecclesiastico usui attidissent nautæ qui e Gallico sinu in Angliam, provecti librorum copiam apportassent_). Among many other books, he saw one containing the whole of the Old and New Testaments, which he at length bought: and William of Malmesbury, who wrote his life in the twelfth century, tells us it was still preserved at that place."