(Potassium dichromate. Bichromate of Potash.)

Chrome is a modern mordant, unknown to the dyer of fifty years ago. It

is excellent for wool and is easy to use and very effective in its

action. Its great advantage is that it leaves the wool soft to the

touch, whereas the other mordants are apt to harden the wool. The wool

should be boiled for 1 to 1-1/2 hours with bichromate of potash in the

proportion of 2 to 4 per cent of the wool. It is then washed well and

immediately dyed. Wool mordanted with chrome should not be exposed to

light, but should be kept well covered with the liquid while being

mordanted, else it is liable to dye unevenly. An excess of chrome

impairs the colour, 3 per cent of chrome is a safe quantity to use for

ordinary dyeing. It should be dissolved in the bath while the water is

heating. The wool is entered and the bath gradually raised to the

boiling point, and boiled for 3/4 of an hour.