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Sizing or size is a substance that is applied to, or incorporated into, other materials—especially papers and textiles—to act as a protective filler or glaze. Sizing is used in papermaking and textile manufacturing to change the absorption and wear characteristics of those materials.


Sizing is used for oil-based surface preparation for gilding (sometimes called mordant in this context). It is used by painters and artists to prepare paper and textile surfaces for some art techniques.


Sizing is used during paper manufacture to reduce the paper's tendency when dry to absorb liquid, with the goal of allowing inks and paints to remain on the surface of the paper and to dry there, rather than be absorbed into the paper. This provides a more consistent, economical, and precise printing, painting, and writing surface. This is achieved by curbing the paper fibers' tendency to absorb liquids by capillary action. In addition, sizing affects abrasiveness, creasibility, finish, printability, smoothness, and surface bond strength and decreases surface porosity and fuzzing.

There are three categories of papers with respect to sizing: unsized (water-leaf), weak sized (slack sized), and strong sized (hard sized). Waterleaf has low water resistance and includes absorbent papers for blotting. Slack sized paper is somewhat absorbent and includes newsprint, while hard sized papers have the highest water resistance, such as coated fine papers and liquid packaging board.

There are two types of sizing: internal sizing, sometimes also called engine sizing, and surface sizing (tub sizing). Internal sizing is applied to almost all papers and especially to all those that are machine made, while surface sizing is added for the highest grade bond, ledger, and writing papers.

Surface sizing

Surface sizing solutions consist of mainly modified starches and sometimes other hydrocolloids, such as gelatine, or surface sizing agents such as acrylic co-polymers. Surface sizing agents are amphiphilic molecules, having both hydrophilic (water-loving) and hydrophobic (water-repelling) ends. The sizing agent adheres to substrate fibers and forms a film, with the hydrophilic tail facing the fiber and the hydrophobic tail facing outwards, resulting in a smooth finish that tends to be water-repellent. Sizing improves the surface strength, printability, and water resistance of the paper or material to which it is applied. In the sizing solution, optical brightening agents (OBA) may also be added to improve the opacity and whiteness of the paper or material surface.

Internal sizing

Internal sizing chemicals used in papermaking at the wet end are alkyl succinic anhydride (ASA), alkyl ketene dimer (AKD) and rosin. By making the paper web more hydrophobic, the sizing agents influence dewatering and retention of fillers and fibers in the paper sheet. Next to paper quality, internal sizing agents' main effect is on runability of the paper machine.


While sizing is intended to make paper more suitable for printing, it also makes printing paper less durable and poses a problem for preservation of printed documents. Sizing with starch was introduced quite early in the history of papermaking. [1] Dard Hunter in Papermaking through Eighteen Centuries [2] corroborates this by writing, "The Chinese used starch as a size for paper as early as A.D. 768 and its use continued until the fourteenth century when animal glue was substituted." [2] In the early modern paper mills in Europe, which produced paper for printing and other uses, the sizing agent of choice was gelatin, as Susan Swartzburg writes in Preserving Library Materials': "Various substances have been used for sizing through the ages, from gypsum to animal gelatin." [3] Hunter describes the process of sizing in these paper mills in the following:

The drying completed, the old papermakers dipped their paper into an animal size that had been made from the parings of hides, which they procured from the parchment-makers. It was necessary to size that paper so that it would be impervious to ink, but sizing was more needed in writing than in printing papers. Many books of the fifteenth century were printed upon paper that had not been sized, this extra treatment not being essential for a type impression. The sizing was accomplished by a worker holding a number of sheets by the aid of two wooden sticks, and dipping the paper into the warm gelatinous liquid. The sheets were then pressed to extract the superfluous gelatine. This crude method of sizing the paper was extremely wasteful as many sheets were torn and bruised beyond use. The sizing room of the early paper mills, was, for this reason, known as the 'slaughter-house'. [2]

With the advent of the mass production of paper, the type of size used for paper production also changed. As Swartzburg writes, "By 1850 rosin size had come into use. Unfortunately, it produces a chemical action that hastens the decomposition of even the finest papers." [4] In the field of library preservation it is known "that acid hydrolysis of cellulose and related carbo-hydrates [sic] is one of the key factors responsible for the degradation of paper during ageing." [5] Some professional work has focused on the specific processes involved in the degradation of rosin-sized paper, [6] in addition to work on developing permanent paper and sizing agents that will not eventually destroy the paper. [7] An issue on the periphery to the preservation of paper and sizing, is washing, which is described by V. Daniels and J. Kosek as, "The removal of discolouration ... in water is principally effected by the dissolution of water-soluble material; this is usually done by immersing paper in water." [8] In such a process, surface level items applied to the paper, such as size in early paper making processes as seen above, have the possibility of being removed from the paper, which might have some item specific interest in a special collections library. With later processes in paper making being more akin to "engine sizing," as H. Hardman and E. J. Cole describe it, "Engine sizing, which is part of the manufacturing process, has the ingredients added to the furnish or stock prior to sheet formation," [9] the concern for the removal of size is less, and as such, most literature focuses on the more pressing issue of preserving acidic papers and similar issues.


Sizing is a term used for any substance which is applied to a surface before gilding in order to ensure adhesion of the thin gold leaf to the substrate. Egg whites have often been used as sizing; the Ancient Egyptians sometimes used blood. [10] Other commonly used traditional materials for gold leaf sizing are rabbit skin glue diluted and heated in water (water gilding), and boiled linseed oil (oil gilding); modern materials include polyvinyl acetate.

Textile warp sizing

Sizing the warp Slashing or startching the warp - cropped.jpg
Sizing the warp

Textile warp sizing, also known as tape sizing, of warp yarn is essential to reduce breakage of the yarn and thus production stops on the weaving machine. On the weaving machine, the warp yarns are subjected to several types of actions i.e. cyclic strain, flexing, abrasion at various loom parts, and inter yarn friction.

With sizing, the strength — abrasion resistance — of the yarn will improve and the hairiness of yarn will decrease. The degree of improvement of strength depends on adhesion force between fiber and size, size penetration, as well as encapsulation of yarn. Different types of water soluble polymers called textile sizing agents/chemicals such as modified starch, polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), and acrylates are used to protect the yarn. Also wax is added to reduce the abrasiveness of the warp yarns. The type of yarn material (e.g. cotton, polyester, linen), the thickness of the yarn, and the type of weaving machinery will determine the sizing recipe.

The sizing liquor is applied on warp yarn with a warp sizing machine. After the weaving process the fabric is desized (washed).

Sizing may be done by hand, or in a sizing machine. [11]

See also

Related Research Articles

Starch glucose polymer used as energy store in plants

Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants as energy storage. It is the most common carbohydrate in human diets and is contained in large amounts in staple foods like potatoes, maize (corn), rice, and cassava, as well as in the grain Emmer wheat, from which is produced a cultivated white starch.

Textile Material produced by twining, weaving, felting, knotting, or otherwise processing natural or synthetic fibers

A textile is a flexible material consisting of a network of natural or artificial fibers. Yarn is produced by spinning raw fibres of wool, flax, cotton, hemp, or other materials to produce long strands. Textiles are formed by weaving, knitting, crocheting, knotting, tatting, felting, or braiding.

Papermaking Economic sector

Papermaking is the art of making paper and cardboard, which are used widely for printing, writing, and packaging, among many other purposes. Today almost all paper is manufactured using industrial machinery, while handmade paper survives as a specialized craft and a medium for artistic expression.

<i>Chine-collé</i> printmaking technique

Chine-collé is a printmaking technique in which the image is transferred onto a surface that is bonded onto a heavier support in the printing process. One purpose is to allow the printmaker to print on a much more delicate surface, such as Japanese paper or linen, that pulls finer details off the plate. Another purpose is to provide a background colour behind the image that is different from the surrounding backing sheet.

Satin Smooth, lustrous fabric, usually of silk or synthetic fiber, woven with a long-float satin binding in warp or weft

Satin refers to the weave of a fabric rather than the material. It typically has a glossy surface and a dull back, one of three fundamental types of textile weaves along with plain weave and twill. The satin weave is characterized by four or more fill or weft yarns floating over a warp yarn, four warp yarns floating over a single weft yarn. Floats are missed interfacings, for example where the warp yarn lies on top of the weft in a warp-faced satin. These floats explain the high luster and even sheen, as unlike in other weaves, the light reflecting is not scattered as much by the fibres. Satin is usually a warp-faced weaving technique in which warp yarns are "floated" over weft yarns, although there are also weft-faced satins. If a fabric is formed with a satin weave using filament fibres such as silk, polyester or nylon, the corresponding fabric is termed a satin, although some definitions insist that the fabric be made from silk. If the yarns used are short-staple yarns such as cotton, the fabric formed is considered a sateen.

Calender series of hard pressure rollers that produces a surface effect on fabric, paper, or plastic film

A calender is a series of hard pressure rollers used to finish or smooth a sheet of material such as paper, textiles, or plastics. Calender rolls are also used to form some types of plastic films and to apply coatings. Some calender rolls are heated or cooled as needed. Calenders are sometimes mis-spelled calendars.

Desizing is the process of removing the size material from warp yarns after a textile fabric is woven.

Textile manufacturing is a major industry. It is based on the conversion of fibre into yarn, yarn into fabric. These are then dyed or printed, fabricated into clothes. Different types of fibres are used to produce yarn. Cotton remains the most important natural fibre, so is treated in depth. There are many variable processes available at the spinning and fabric-forming stages coupled with the complexities of the finishing and colouration processes to the production of a wide range of products.

Textile printing method for applying patterns to cloth using printing techniques

Textile printing is the process of applying colour to fabric in definite patterns or designs. In properly printed fabrics the colour is bonded with the fibre, so as to resist washing and friction. Textile printing is related to dyeing but in dyeing properly the whole fabric is uniformly covered with one colour, whereas in printing one or more colours are applied to it in certain parts only, and in sharply defined patterns.

Plain weave method of weaving cloth in which each warp and weft thread crosses over/under every other thread

Plain weave is the most basic of three fundamental types of textile weaves. It is strong and hard-wearing, and is used for fashion and furnishing fabrics.

The manufacture of textiles is one of the oldest of human technologies. To make textiles, the first requirement is a source of fibre from which a yarn can be made, primarily by spinning. The yarn is processed by knitting or weaving, which turns yarn into cloth. The machine used for weaving is the loom. For decoration, the process of colouring yarn or the finished material is dyeing. For more information of the various steps, see textile manufacturing.

Japanese tissue Thin, strong paper made from vegetable fibers

Japanese tissue is a thin, strong paper made from vegetable fibers. Japanese tissue may be made from one of three plants, the kōzo plant, the mitsumata shrub and the gampi tree. The long, strong fibers of the kōzo plant produce very strong, dimensionally stable papers, and are the most commonly used fibers in the making of Japanese paper (washi). Tissue made from kōzo, or kōzogami (楮紙), comes in varying thicknesses and colors, and is an ideal paper to use in the mending of books. The majority of mending tissues are made from kōzo fibers, though mitsumata and gampi papers also are used.

Paper Thin material for writing, printing, etc.

Paper is a thin sheet material produced by mechanically and/or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, packaging, decorating, writing, cleaning, filter paper, wallpaper, book endpaper, conservation paper, laminated worktops, toilet tissue, currency and security paper and a number of industrial and construction processes.

Finishing (textiles) any process performed after dyeing the yarn or fabric to improve the look, performance, or "hand" (feel) of the finished textile or clothing

In textile manufacturing, finishing refers to the processes that convert the woven or knitted cloth into a usable material and more specifically to any process performed after dyeing the yarn or fabric to improve the look, performance, or "hand" (feel) of the finish textile or clothing. The precise meaning depends on context.

History of paper History of paper

Paper is a thin nonwoven material traditionally made from a combination of milled plant and textile fibres. It is primarily used for writing, artwork, and packaging; it is commonly white. The first papermaking process was documented in China during the Eastern Han period traditionally attributed to the court official Cai Lun. During the 8th century, Chinese papermaking spread to the Islamic world, where pulp mills and paper mills were used for papermaking and money making. By the 11th century, papermaking was brought to Europe. By the 13th century, papermaking was refined with paper mills utilizing waterwheels in Spain. Later European improvements to the papermaking process came in the 19th century with the invention of wood-based papers.

Postage stamp paper

Postage stamp paper is the foundation or substrate of the postage stamp to which the ink for the stamp's design is applied to one side and the adhesive is applied to the other. The paper is not only the foundation of the stamp but it has also been incorporated into the stamp's design, has provided security against fraud and has aided in the automation of the postal delivery system.

Paper chemicals

Paper chemicals designate a group of chemicals that are used for paper manufacturing, or modify the properties of paper. These chemicals can be used to alter the paper in many ways, including changing its color and brightness, or by increasing its strength and resistance to water.

Wet processing engineering is one of the major streams in textile engineering refers to textile chemical processing engineering and applied science. The other three streams in textile engineering are yarn manufacturing engineering, fabric manufacturing engineering and garments manufacturing engineering.

The surface chemistry of paper is responsible for many important paper properties, such as gloss, waterproofing, and printability. Many components are used in the paper-making process that affect the surface.

Red rosin paper

Red rosin paper is a 100% recycled heavy duty felt paper used in construction such as underlayment under flooring and siding. The name "rosin-sized sheathing paper", commonly used to describe the material, comes from the rosin used in the paper, the process of sizing it to add the rosin, and its use by builders. "Alum-rosin size was invented by Moritz Friedrich Illig in Germany in 1807..." and is known to have been used as a building paper by 1850.


  1. Robert Henderson Clapperton and William Henderson. Modern Paper-making. 3rd ed. (Oxford: Basil Blackwell, 1947), 120.
  2. 1 2 3 Dard Hunter, Papermaking through Eighteen Centuries. (New York: William Edwin Rudge, 1930), 141. available on line Archived 2013-10-29 at the Wayback Machine
  3. Susan G. Swartzburg, Preserving Library Materials: A Manual. 2nd ed. (Metuchen, NJ: The Scarecrow Press, 1995), 131.
  4. Swartzburg, Preserving Library Materials, 131.
  5. Altaf H. Basta and others, "The Role of Neutral Rosin-Alum Size in the Production of Permanent Paper." Restaurator: International Journal for the Preservation of Library and Archival Material, 27, no. 2 (2006): 67.
  6. Houssni El-Saied, Altaf H. Basta and Mona M. Abdou. "Permanence of Paper 1: Problems and Permanency of Alum-Rosin Sized Paper Sheets from Wood Pulp." Restaurator: International Journal for the Preservation of Library and Archival Material, 19, no. 3 (1998): 155–171.
  7. Altaf H. Basta and others, "The Role of Neutral Rosin-Alum Size in the Production of Permanent Paper," 67-80.
  8. V. Daniels and J. Kosek, . "Studies on the Washing of Paper, Part 1: The Influence of Wetting on the Washing Rate." Restaurator: International journal for the Preservation of Library and Archival Material, 25, no. 2 (2004): 81.
  9. H. Hardman, and E. J. Cole. Paper-making Practice. (Manchester: Manchester University Press, 1960), 112.
  10. Glawson, Rick. "A Treatise on Gold Size". The Letterheads. Archived from the original on 13 May 2013. Retrieved 19 April 2013.
  11. Schutz, R.A. (12–16 September 1977). "Theoretical and Practical Aspects of Sizing today and tomorrow". Third international sizing symposium.