Acid Free:
Paper that is free from any acid content or other substance likely to have a detrimental effect on the paper or its longevity.
Alum:
A complex salt, most commonly aluminum sulphate added with rosin to pulp while it is in a beater as a sizing agent to impart a harder and more-resistant surface to the finished sheet. It also acts as a preservative and a mordant for fixing colours.
Archival Paper:
A paper with long-lasting qualities, acid free, lignin free, usually with good colour retention.
Bast Fibre:
The inner bark of such plants as banana, flax, hemp, ramie which when separated out from the outer bark provides fibres suitable for papermaking
Beater:
A machine which alters or modifies the properties of fibre.
Bleach:
A chemical used to whiten paper pulp, a solution of chlorine or similar chemical. Usually, hydrogen peroxide or bleaching power is used as bleaching agent.
Brittleness:
The property of paper to crack or break when bent or embossed.
Brightness:
Paper’s ability to reflect white light. Titanium dioxide mainly used to add brightness and opacity to paper.
Buffering Agent:
It is an alkaline substance, usually calcium carbonate or magnesium carbonate, purposely added by the papermaker to protect the paper from acidity in the environment.
Calendaring:
A pressing process used to smooth or glaze a sheet of paper during the finishing process.
Cellulose:
The main part of the cell wall of a plant.
Cotton Fibre /Linters /Rags:
The soft white filaments attached to the seeds of the cotton plant. Cotton fabric is made from long fibres removed from the seeds by ginning operation. Short fibres called linters, unsuitable for cloth but good for papermaking, are left. There are three grades of cotton fibres used in the papermaking process – first cut or lint; mill cut and second cut. Cotton is the purest form of cellulose produced in nature and it requires the least amount of processing before it can be used. Pulp can be produced from either cotton linter or rags.
Couch:
The action of transferring a wet sheet of paper from the mold onto damp felt.
Deckle:
A wooden frame that fits over a paper mould to prevent the pulp from running off the edges. It is also establishes the size of a handmade sheet during making.
Deckle Edges:
The wavy, feathered or ragged edges of a sheet of handmade paper on four sides caused by the deckle frame where pulp thins towards the edges of the mould.
Dyes:
A water-soluble colouring agent which usually penetrates and become attached to the fibre. Types of dyes include: direct dyes, fibre-reactive dyes, that form a chemical bond with the fibres; and natural dyes, derived from natural sources such as pomegranate skin, onion skin, henna tops, marigold flower, dry tea leaves etc.
Fibres:
The basis of a sheet of paper.
Fourdrinier:
The name of a type of paper machine in which paper is made at high speed in continuous web – machine made paper.
Gelatin:
A type of size obtained from animal tissues applied to the surface of paper to make it impervious to water and to aid resistance to bleeding during printing. Also imparts surface strength to watercolour and drawing papers.
gsm / gm²:
Unit of measuring paper weight. It means grams per square metre.
Hollander:
The paper beating machine that was invented in Holland.
Laid Mould:
A wooden frame for the forming of pulp into sheets of paper in which the characteristic of closely spaced parallel lines (can be seen in dry paper when it is held up to light) held in place by wire worked in the perpendicular direction to the strips.
Lignin:
The fibre bonding material found mainly in woody plant. It rejects water and resists bonding and therefore must be removed from the fibres before the paper making process.
Mould:
The basic tool of a Western hand papermaking which consists of a wooden frame and removal deckle.
pH:
The pH value is a measure of the strength of the acidity or alkalinity of a paper. The pH scale runs from 0 to 14. 7pH represents a balance between the acid and alkaline components and is a neutral solution. Above 7pH indicates more alkalinity and below 7pH indicates more acidic.
Pulp:
The ‘stuff’ used in papermaking process.
Ream:
500 sheets of paper.
Rosin:
One of the most commonly used internal sizing agent for paper. It is acidic in nature and detrimental to the permanence of paper.
Sizing:
A solution used to make the paper moisture resistant in varying degrees. Size can be added at two stages of the papermaking process. The degree of sizing of paper determines their resistance to the penetration of moisture. Internal sizing / Engine sizing / Beater sizing describes moisture resistant pulps which receive sizing treatment in the beater. Tub sizing – after manufacture, when the paper has been dried, some papers are passed through a solution of gelatine (or other size) contained in a trey or tub. Other surface sizes include casein and starch.
Vat:
A tub that holds the wet pulp.
Vellum:
The prepared inner side of calfskin; the term vellum can be used as an imitation of this type of surface in another paper.
Waterleaf:
Used to describe a paper that contains no sizing and is generally very absorbent, like blotting paper.
Watermark:
It is a translucent marking made in paper, barely noticeable except when the sheet is held up against the light or is placed against respective contrast background. The design is generally formed out of copper wire and attached as a mirror image to the flat surface of the mold. Where the watermark device is attached to the screen of the mold a raised surface occurs, because the actual quantity of pulp is less over the raised part than over the rest of the sheet. When the paper gets dried the design appears as a slightly thinner layer of paper.
Wove Mould:
A mould in which the covering screen is made by woven wire (similar to warp and weft in a cloth). Opposite to laid mould.
