Routine finishes are applied to almost all fabrics with an aim to improve their appearance. A finish is anything that is done to a fabric after weaving or knitting, to changes its appearance, hand and performance. When a finish is applied, say on cotton, it might become more shiny, stronger or resist shrinking on washing. Similarly, other finishes may make the fabric softer or stiffer; water or stain resistant; coloured or designed.
Bleaching has to be done very carefully as the chemical which can destroy the colour may also damage the fabric to some extent. Hydrogen peroxide is a universal bleach which can be applied to all kinds of fabrics.
Stiffening gives body, smoothness and luster to the fabric. This practice is sometimes used to cheat the customer. You must have observed that some times if you rub a fabric between your hands, some white powder comes out. It is because the fabric has been over-starched. Inferior fabrics are over-starched to look dense and better.