If a book is folio, and two pages of type have been composed, they are placed in proper position upon the imposing stone, and enclosed within an iron or steel frame called a 'chase', small wedges of hard wood termed 'coigns' or 'quoins' being driven in at opposite sides to make all tight. By the four opposing coigns, Which the world together joins. _Pericles_, iii, 1. This is just the description of a forme in folio where two quoins on one side are always opposite to two quoins on the other, thus together joining and tightening all the separate stamps. In a quaint allegorical poem, published anonymously about the year 1700, in which the mystery of man's redemption is symbolised by the mystery of Printing, the author commences thus: Great blest Master Printer, come Into thy Composing-room; and after 'spiritualising' the successive operations of the workman thus touches upon the quoins: Let the Quoins be thy sure Election, Which admits of no Rejection; With which our Souls being joined about, Not the least Grace can then fall out. Here, the idea of joining together by quoins so that nothing shall fall out, is just the same as in the couplet quoted from Shakspere. The tightening of these quoins by means of a wooden-headed mallet, (There is no more conceit in him than is in a mallet, _2 Henry IV_, ii, 4), is called 'locking up', an exclusively technical term. The expression, however, occurs in 'Measure for Measure', IV, 2, Fast locked up in sleep, where the idea conveyed is the same. The 'Forme' worked off and the metal chase removed, leaving the pages 'naked', affords the Poet the following simile, which although not carrying to the popular ear any typographical meaning, was doubtless suggested by Shakspere's former experience of the workshop: And he but _naked_ though _locked up_ in steel. _2 Henry VI_, iii, 2. The primary idea of 'locking up' had, doubtless, reference to 'armour'; the secondary to printing, as shown by the use of the word 'naked'. The forme then went to the Press-room, where considerable ingenuity was required to make 'register'; that is, to print one side so exactly upon the other, that when the sheet was held up to the light the lines on each side would exactly back one another. The accuracy of judgment required for this is thus glanced at: _Eno._ But let the world rank me in _register_ A master-leaver and a fugitive. _Antony and Cleopatra_, iv, 9. When the green-eyed Othello takes his wife's hand and exclaims: Here's a young and sweating devil, _Othello_, iii, 4,