Parchmentising or parchmentizing is a kind of aesthetic finish for textiles. It is a finishing treatment for

cellulose Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important s ...

fabric Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, and different types of fabric. At first, the word "textiles" only referred to woven fabrics. However, weaving is no ...

that stiffens the fabric and imparts a degree of translucency.

Parchment

Parchment was a material for writing created in

ancient times Ancient history is a time period from the History of writing, beginning of writing and recorded human history through late antiquity. The span of recorded history is roughly 5,000 years, beginning with the development of Sumerian language, ...

. It was created with animal skin. It means "stuff from Pergamos" in both the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

and

Greek language Greek (, ; , ) is an Indo-European languages, Indo-European language, constituting an independent Hellenic languages, Hellenic branch within the Indo-European language family. It is native to Greece, Cyprus, Italy (in Calabria and Salento), south ...

Eumenes II Eumenes II Soter (; ; ruled 197–159 BC) was a ruler of Pergamon, and a son of Attalus I Soter and queen Apollonis and a member of the Attalid dynasty of Pergamon. Biography The eldest son of king Attalus I and queen Apollonis, Eumenes was pr ...

developed parchment when

papyrus Papyrus ( ) is a material similar to thick paper that was used in ancient times as a writing surface. It was made from the pith of the papyrus plant, ''Cyperus papyrus'', a wetland sedge. ''Papyrus'' (plural: ''papyri'' or ''papyruses'') can a ...

was banned for export to Pergamos by

Ptolemy V Epiphanes Ptolemy V Epiphanes Eucharistus (, ''Ptolemaĩos Epiphanḗs Eukháristos'' "Ptolemy the Manifest, the Beneficent"; 9 October 210–September 180 BC) was the Pharaoh, King of Ptolemaic Egypt from July or August 204 BC until his death in 180 BC. ...

. The skin of sheep, goats, or cattle was used to create parchment. The parchmentising process involves the application of

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...

to cellulosic textiles in order to achieve the characteristics of parchment.

Organdy

Parchmentising offers a stiffened and somewhat translucent finish.

Organdy Organdy, also spelled Organdie, is a kind of fabric. It is a lightweight, balanced plain weave made of cotton with features of sheerness and crispness. Characteristics Organdy is a stiffened material; sheerest among its peers, which include l ...

is one of the sheerest cloths produced by the process.

Development

Parchmentising was described in 1850 by John Mercer, who treated cotton with solutions of 110–125 °Tw sulfuric acid, at room temperature, followed by washing. Mercer observed that the treated fabric was soft like fine wool when treated at 110°Tw, shrank and stiffened at 114°Tw, or shrank, stiffened, and became semi-transparent from 116 to 125°Tw. In general, treating indefinitely with concentrations below 110°Tw (64%) only swells and shrinks the fabric, while higher concentrations produce the stiff, translucent parchment-like effect in a few seconds, with some loss of tensile strength. Textile makers have combined sulfuric acid treatment with other processes to achieve different effects. For example,

Mercerising Mercerisation is a textile finishing treatment for cellulose fabric and yarn, mainly cotton and flax, which improves Dyeing, dye uptake and tear strength, reduces Shrinkage (fabric), fabric shrinkage, and imparts a silk-like Luster (textiles), l ...

cotton fabric before acid treatment appears to make it more susceptible to treatment at lower concentrations of sulfuric acid. At about 106 °Tw the Mercerised lustre is removed and the fabric becomes fuller, softer, and more wool-like, similar to a crêpe. The parchmentising effect is still present at higher concentrations, and may be obtained as low as 107.5 °Tw with somewhat longer treatment, perhaps a few minutes. Acid and alkaline treatments are sometimes applied several times in alternation, and patterns may be created by locally applying a

resist A resist, used in many areas of manufacturing and art, is something that is added to parts of an object to create a pattern by protecting these parts from being affected by a subsequent stage in the process. Often the resist is then removed. For ...

before or between treatments. At every stage the treatment is stopped by washing and neutralizing the fabric. After acid treatment and washing, a heavy

calender A calender is a series of hard pressure rollers used to finish a sheet of material such as paper, textiles, rubber, or plastics. Calender rolls are also used to form some types of plastic films and to apply coatings. Some calender rolls are ...

, sometimes heated, can be applied to the wet or dried fabric to vary its translucency.

References

{{fabric Textile industry Fibers Cotton 1850 introductions Properties of textiles