Dyeing
The next operation is that of dyeing or coloring, and if convenient, and the hats fine, each hat should be upon its respective block when in the color kettle, great care being observed to keep the square from abrasion, as the least rub may deprive a napped hat of its fur at that exposed and important part. Most generally, however, the hats are colored without a block, the blocking being performed as soon after the dyeing and washing as possible in boiling water.
The ordinary ingredients for black are, for 12 dozen,
144 lbs. of logwood, chipped, or its value in extract.
12 lbs. of green sulphate of iron or copperas.
7½ lbs. of French verdigris.
The kettle should never boil nor exceed 190 degrees, and during the operation the hats must be repeatedly taken out and exposed to the action of the oxygen of the air, so as to strike a deeper color, and during the necessary exposure to these airings, the time is improved by having two suits of hats going on at the same time.
From six to twelve hours are required to complete the operation. The shorter the time the hats are in the dye, compatible with the deepness of the color, the better will be the goods, as boiling extracts the gelatine of the hair and makes the nap brittle, which is seen by comparing dyed articles with those that are of a native color.