The projections of a board beyond the head-, tail-, and fore-edges of a bookblock are called squares. The origin of the term is not recorded, but a medium square may be taken as a projection which is equal to the thickness of the board. Below this measurement, the squares can be described as narrow and beyond it, as wide. Measuring the width of squares is not always easy, as bookblocks which have dropped between their boards because of vertical storage will give false measurements, and the binders of cheaper books often took little trouble either to cut the board edges parallel to the bookblock or even to cut them straight. An approximate assessment relative to the size of the bookblock is often therefore the most satisfactory. It may also be found that the squares are not of equal width on each edge, often leaving the fore-edge noticeably wider than the head- and tail-edges, but also, on occasion, with unequal squares at head and tail. The boards may also be cut to the size of the bookblock, cut flush together with the edges of the bookblock, or, in the case of Greek bindings, the bookblock may be cut level with the boards after it has been sewn to the boards. In all these cases, there will be no squares. On rare occasions, boards may be cut smaller than the bookblock (undersize), most often where the bookblock is uncut and retains its deckle edges. Care must be taken, however, not to mistake unequal squares on wooden boards which are the result of the subsequent shrinking of the wood across the grain with unequal squares which were intended by the binder. In bindings with squares this can result in boards without squares on the fore-edge (if the grain direction of the wooden board is vertical) and in bindings originally without squares, it can result in the wooden boards drawing back several millimetres from the edges of the bookblock. Boards made from paper are not liable to this type of shrinkage. However, the paper boards used in parchment-covered laced-case bindings with boards were cut without squares on the fore-edge if the cover was to have cover extensions, whilst retaining squares at head and tail. The definition of squares given above works only for boards, but for limp covers of paper or parchment, the term 'squares' is not particularly useful, as the thickness of the cover is almost always going to be narrower than the projection of the cover beyond the bookblock. Measurements are not necessarily useful as the width may vary within each side of the cover, let alone between the two sides. Identifying only those which are flush, or unusually narrow or wide is perhaps the most practical way of dealing with this question.
den delen av permen eller omslaget som går utenfor bokblokkas format