The ABC of paper – deciphering papermaking vocabulary
Paper has a rich history dating back thousands of years. Explore the rich technical vocabulary of the papermaking world with its highly specific words and expressions.
Here we explain some of the terms based on extracts, loosely translated as the French terms do not always have exact English equivalents, from a French dictionary of papermaking know-how, L’abécédaire du papier, un dictionnaire des savoir-faire, published by Éditions Pyramyd at the beginning of this year. This book written by Valentine Dubard De Gaillarbois and Tomoko Kawamura contains all their expertise in 160 pages entirely dedicated to paper.
In a series of entries presented alphabetically, the book reveals the secrets of how paper has been made and used through the ages and offers a new and fascinating perspective on this universe.
Among the insights shared are definitions of some of the papermaking terms used at the Arches paper mill:
Amoureux
“Amoureux (amorous) is a French term used to describe paper that is suitable for printing, as it espouses the relief of the typeface and readily absorbs ink. It is slightly bulky or ‘hollow’ to withstand deformation and must not be over-sized or too stiff so that it can take greasy inks.”
Edges
“The edges of a sheet of paper tell us a lot. They tell you its history, whether they are intact or they have been cut cleanly with a blade, or roughly torn, after folding or moistening. Torn edges are recognisable by the presence of fibres of different lengths. They look different to deckle edges that have been left intact.”
Natural deckle or feathered edge of a sheet of ARCHES® paper
Water
“Water is indispensable to papermaking. It is involved in all the stages of preparing the fibres, then it serves as a vector when the fibre mat is formed before being gradually removed.”
Look-through
“The look-through of a paper reveals how the fibres are distributed in all dimensions: on the surface and in the thickness of the sheet. It is observed by transparency as the name suggests.”
The sheet wire is a thicker layer sewn onto the wire mould or integrated into the machine wire to create a separation by one or more raised lines… At the location of the sheet wire, the fibre mat is thinner because the fibres cannot be deposited as thickly, forming lines where the paper is weaker and can more easily be torn into sheets. After separation by tearing, the edges of the sheets are irregular. These are known as deckle edges.”
Dry line
“The dry line on a paper machine is the location where the surface of the fibre mat changes from glossy to matt. This change in appearance means that the drainage of the pulp suspension is advanced enough for the fibres to have lost their mobility and to have been fixed in the fibre mat. The grammage of the sheet is determined at this moment, at the end of the forming zone.”
“Linters are the fibres that remain on cotton seeds after ginning. These are a waste* product which is recovered for use in the paper or other industries. Linter fibres are shorter than the cotton fibres used for textiles.”
* valuable
Refining
“Refining (or beating) is a mechanical treatment of plant fibres to obtain paper pulp. It modifies the mechanical and optical properties, the surface quality and printability of papers. Refiners act by applying compression and shear forces on the fibres. They cause delamination of the layers of the cell wall, like a series of gloves being taken off a hand one after the other. This exposes the cellulose fibrils and increases the surface area of the fibres, allowing for improved bonding between the fibrils and also with the other fibres.”
Extract from the book “L’abécédaire du papier, un dictionnaire des savoir-faire”
Top side – in the top image, seen lit from the front, the watermark is in counter-relief: this is the wire side. In the bottom image, the same sheet is turned round and viewed by transmitted light; the contours of watermark are less sharp and it is not in relief: this is the top or felt side. The legibility of the watermark and the depth of the counter-relief show that the paper was made on a machine with a cylinder mould. Johannot paper.
