The term “spine,” like the “head,” “tail,” and “shoulders” of a book, belongs to a broader set of anthropomorphic terminology used in bookmaking. The spine often bears the book’s title, serving not only structural purposes but also as the primary site of encounter on a bookshelf as the only outward-facing side. The counter-facing side of the spine, known as the “fore-edge,” similarly implies an anterior orientation (a frontal face) and can only be defined spatially through its relation to the bound spine (a back face). Despite the terms, the book has always possessed these two faces: one defined through encounter, the other through production.
In conventional bookmaking sequences, substrates are first produced as separate sheets, marks are then printed onto each sheet, and only later are they bound together to form a spine.
3D printing, however, follows an additive model in which structure emerges through sequential layering. With the XY-for-Z printing method, the spine of the book is printed first, followed by the substrates and marks, ending with the fore-edge. The book materialises simultaneously as a singular object, and is bound at the base before its pages are fully materialised. The spine becomes origin rather than conclusion, the fore-edge becoming not merely its spatial opposite but its temporal counterpart. The XY-for-Z method not only reorients book production in space, but also reverses the conventional sequence and, in doing so, collapses binding into fabrication itself.
This is the Janus bind, named after the two-faced Roman god Janus who presides over beginnings and endings, transitions and dualities, and time itself. One face of Janus is said to look into the past, the other toward the future. Likewise, beyond reversing the conventional sequence of bookmaking, this 3D printed book emerges from the print bed with two faces: one turned toward the past of bookmaking, the other toward its future.