Defining some terms may make these posts easier to understand. I have chosen some words when a traditional term was not known to me. The terms are in italics; accompanying text and photos are intended to define and explain their meaning.
~frame sides: The two longer parts of the mould frame parallel to the laid wires. Ribs are set perpendicular to the sides, both ends being fixed in holes drilled there.
~frame ends: The two shorter parts of the mould frame parallel to the ribs.
(above) The underside of a wove mould. This photo identifies the frame sides and frame ends along with a few other parts of a paper mould.
~chain wire / chain wires: These words are especially confusing to use. I will use the singular “chain wire” in these posts to mean a single pair of wires that spiral around each other, binding laid wires side by side to make a facing. Visually it appears as a single line of wire, resembling a miniature chain, crossing the laid wires at a right angle. I will use the plural “chain wires” to refer to more than one of these structures. Examples of the two uses might include: “Each rib has a chain wire positioned above it.” And “All of the ribs have chain wires positioned above them.” (It is awkward to write many times about “chain wire pairs”. And what is the plural of “chain wire pairs”?)
(above) An excerpt from a drawing showing the process of making a laid facing in a loom. It provides a simplified view of the structure of a laid facing including a few laid wires, a chain wire and a twist.
~laid facing: The uppermost wires of a laid mould. The porous wire surface on which macerated cellulose fibers are collected when forming sheets of paper.
(above) This photo shows a laid facing being fitted to make a ‘single faced laid’ mould. This is the simplest and oldest type of European style paper mould. Another type of mould, ‘double faced laid’, uses this same type of facing supported upon an additional layer of wires, called ‘backing’.
~wove facing: The uppermost wires of a wove mould. These are in the form of a fine screen of woven wire that collects fibers to make a sheet of wove paper.
(above) A wove facing is being trimmed and fitted to its mould. A wove mould always has two layers of wire and is sewn in two stages.
~backing: A layer of wires that lies beneath a laid or wove facing to support it from below. Backing is prepared on a loom like a laid facing but with wires spaced much further apart.
(above) Backing being fitted to what will become a double faced laid mould.
(below) The very bottom of a large backing that is finished and ready to cut off of the loom. Three half-twists in the chain wires keep the laid wires widely spaced. The last four laid wires are more closely spaced with two half-twists in the chain wires. Including a few narrow spaces along one edge makes it easier to fit the backing to the mould frame.
~facing laid wires: The long, straight wires that make up a laid facing. There are hundreds of laid wires lying close together in a typical laid facing. They are fastened together by a dozen or so widely spaced chain wires.
~backing laid wires: The long, straight wires that make up a backing; these wires are the same as facing laid wires but spaced further apart with extra twists between them.
(above) Facing laid wires and backing laid wires are shown in this extreme close-up. The red arrows show where two backing laid wires are hidden under laid wires of the facing.
~loose chain wires vs. sewn chain wires: With the exception of one chain wire at each end all of the chain wires of a mould are fastened in place, each being sewn to a rib. The two ‘loose’ chain wires at the ends can’t be sewn to a rib. To secure them they are ‘trapped’, either in a groove in the wooden frame (single faced laid and wove) or between two bridge wires (double faced laid).
(above) The chain wire running across the top of this double faced laid mould is ‘loose’ (not sewn), but it is trapped between bridge wires to keep it from ‘wandering’. The chain wire seen along the bottom of the photo is sewn to its rib.
~bridge wires: Bridge wires are physically the same as laid wires but have a different purpose and are used only in double faced laid moulds. They are straight, stiff wires that bridge the widely spaced backing laid wires to provide a smooth, firm support for the laid facing. Over each rib, a single bridge wire runs alongside and between the two chain wires (one facing, one backing) and is sewn in place as part of a ‘bundle’ of wires. Bridge wires are also used at both ends of a double faced laid mould to provide extra support for the ends of the facing laid wires. They provide a firm base for the laid wires which keeps them from distorting badly when copper edge strips are tacked in place.
(above) Above each rib a single bridge wire is inserted alongside chain wires and between the laid wires of the facing and backing. It crosses the widely spaced laid wires of the backing, providing a smooth, solid support for the upper facing to prevent it from being cinched down unevenly by the stitches that bind it to the rib.
(below). You can see both uses for bridge wires here; at “A” as one piece of the ‘bundle’ of wires sewn to a rib, and at “B” lined up in a group to support the ends of laid wires where they lap over the frame end.
twists: These are extensions of the chain wires that lap over the frame sides.
(above) Extra laid wires have been pulled out to fit a laid facing to its mould leaving this twist a bit loose.
(below) The same twist has been tightened and will be trimmed to fit in the notch. After the mould is sewn all of the twists will be covered by copper edge strips to protect them.
single faced laid: The most basic type of paper mould having a single layer of laid wires sewn directly to the ribs. Until the mid 18th century it was the only type of European style mould. Paper made on this type of mould is distinctive for having ‘shadow zones’ along the chain wires. This is a result of the rate of drainage along the ribs differing from the rate of drainage between the ribs.
(above) It is easy to see that there is only one layer of laid wires in this single faced laid mould. A laid facing is in the process of being sewn to the ribs.
double faced laid: A type of laid mould developed around the middle of the 18th century having two layers of wire. Adding the extra layer (backing) improves drainage and eliminates the uneven formation typical with single faced laid.
(above) Two layers of wire are visible here, identifying this as a double faced laid mould.
wove: Wove moulds were also devised around the middle of the 18th century. Paper made on these moulds lacks the distinctive laid pattern because the facing is a nearly featureless fine woven mesh. Wove moulds require a backing; the wires of the backing keep the relatively soft wire mesh from sagging between ribs.
(above) A wove mould with deckle in place. The support grid of the backing can be seen through the fine wire mesh of the wove facing.
wove backing: The layer of wires devised to support the facing of a wove mould. It resembles a laid facing but with laid wires spaced much further apart.
grid wires: A grid is created on top of the backing to support the wove facing evenly. The grid is made of a single wire strung back and forth between small brass or copper nails. Two rows of stitching between each pair of ribs will secure the facing to the backing.
(above) The wove backing has been completely sewn to the ribs and a grid has been created to provide an even support to which the wove facing will be stitched.
ledge: A shelf or lower level created to support laid wires where they overlap each end of the mould frame. The cut ends of the wires must be protected by a copper strip. It is difficult to keep this strip from distorting the wires when it is tacked down. This can be minimized with careful attention; aiming to support the laid wires at the same level as they are supported by the ribs.
(above) One end of a double faced laid mould with two ledges. The deeper one supports the ends of the backing laid wires. The shallow ledge supports the ends of the facing laid wires.
trap groove: A groove cut along the inner edge of a ledge to ‘trap’ the ‘loose’, unsewn chain wire so it can’t move.
copper edge strip: The narrow strip that is affixed to the top edges of the frame to protect the vulnerable ends of laid wires and twists. Along the ends it also functions to bind the laid wire ends to the mould; holding them in place to align them evenly with the rest of the facing.
(above) A copper strip has been tacked to both ends of this mould. It protects the ‘ragged’ ends of the laid wires while holding the ‘loose’ chain wires (facing and backing) and bridge wires in place. The strips along the sides do less; serving only to protect the twists. If not covered the ends of wire are vulnerable and likely to be snagged and bent. In moulds receiving hard use chain wire twists sometimes ‘escape’ from their covering and will be bent, first one way, then another. They eventually fatigue and break, most likely right at the first laid wire. The chain wire will loosen near the break and laid wires may come loose, too. The copper strips at the ends sometimes work loose, allowing laid wires to protrude and become damaged.
Timothy Moore Bookbinding Tools 