Lea D. Pokorny's lecture about manuscript production. The arrangement of sheets of parchment into gatherings is an important step during manuscript production. In medieval Europe, two general traditions are differentiated by scholars: the insular practice, whereby the sheets are arranged so that hair-sides face flesh-sides in an opening, and the continental practice, whereby like faces like, also referred to as ‘Gregory’s rule’. Medieval Icelandic book production has hitherto been said to have followed, although not always faithfully, the latter practice. In this talk, the construction of gatherings in fourteenth-century Icelandic manuscripts will be examined in order to assert which practice Icelandic book makers followed.