Hodden or wadmel is a coarse kind of cloth made of undyed 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....

, formerly much worn by the peasantry of Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

. It was usually made on small hand-looms by the peasants themselves. Grey hodden was made by mixing black and white fleece

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....

s together in the proportion of one to twelve when weaving. The origin of the word is unknown.

In his poem "A Man's a Man for a' That", Robert Burns wrote

What though on hamely fare we dine,

Wear hodden grey, an' a that;

Gie fools their silks, and knaves their wine;

A Man's a Man for a' that."

Hodden Grey is the name given to the tartan

Tartan

Tartan is a pattern consisting of criss-crossed horizontal and vertical bands in multiple colours. Tartans originated in woven wool, but now they are made in many other materials. Tartan is particularly associated with Scotland. Scottish kilts almost always have tartan patterns...

 worn by members of the London Scottish Regiment, and the Toronto Scottish Regiment (Canada). It was chosen both to avoid inter-clan rivalry and also because, as Lord Elcho said, "A soldier is a man hunter. As a deer stalker chooses the least visible of colours, so ought a soldier to be clad."