Tailoring is a skill a monk share's with the warrior and the rogue. It gives you the ability to improve your armour, repair your armour and even dye your armour.

There are several kinds of "tailored" clothes.

"Good" armour makes your armour class lower by 1 point that normal.
It is also approximetly 20% lighter than usual.

"Fine" armour makes your armour class lower by 2 points that normal.
It is also approximetly 40% lighter than usual.

"Grand" armour makes your armour class lower by 3 points that normal.
It is also approximetly 60% lighter than usual.

"Great" armour makes your armour class lower by 4 points that normal.
It is also approximetly 80% lighter than usual.

Like Herbalism tailoring, on occasion, gives you a Legend mark.
The Higher your legend mark, the more success rate you will have, and the more
chance you will have of attaing a better armour.
Also, your success rate will increase with the use of an assistant.
Please note that 1 day of labour is needed to utilize the mundane tailoring.
Vamilstle's The Warrior has an extensive description of tailoring.

While on a hunt, you may want to use tailoring to repair your items. Depending on its level
Tailoring will either repair your item by 20% or destroy it by 10%. So be carefull, and practice
this skill as much as possible on a shirt or a blouse.

Dyeing Clothe's is another skill attaind after learning Tailoring. With a recognized tailoring
ability (legend of tailor(1) or higher) you will be able to dye clothes with the assisntance of a
respected citezen.
All of the available dye's are catalouged on Raeven and Maiala Kyrkonnel Illustrated Guide to color
Alchemy