Scarlet was a type of fine and expensive wool

Wool

Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....

len cloth common in Medieval England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.

The name derives from the Latin scarlata, from the Arabic

Arabic language

Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...

 siqillat "fine cloth" and that again from the Persian

Persian language

Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan, Tajikistan and countries which historically came under Persian influence...

 saqirlat. The weaving technique also had its origin in Central Asia

Central Asia

Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...

, and made the cloth elastic by twisting the yarn

Yarn

Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or...

. Because of this property, it was often used for stockings and tights.

Scarlet cloth was produced in red, white, blue, green, and brown colors, among others. The most common color was carmine red

Carmine (color)

Carmine is the general term for a particularly deep red color. Some Rubies are colored the color shown below as rich carmine. The deep red color shown below as carmine is the color of the raw unprocessed pigment, but lighter, richer, or brighter colors are produced when the raw pigment is...

, though, which resulted in the double meaning of the word as a color designation.

It is probable that name of the character Will Scarlett in the Robin Hood

Robin Hood

Robin Hood was a heroic outlaw in English folklore. A highly skilled archer and swordsman, he is known for "robbing from the rich and giving to the poor", assisted by a group of fellow outlaws known as his "Merry Men". Traditionally, Robin Hood and his men are depicted wearing Lincoln green clothes....

legends referred to this type of cloth, similarly to the common occupational surnames (e.g. Weaver, Cooper, Fletcher, etc.).