That tunic is a reward for completing the TS quest that begins with reading, (examining), the note you got from the TS guy in the mage tower on the island. If you destroyed your original note, you can buy one from the same guy who gives out the quest.
It is a nice long quest that will take you all the way to lvl 9 or 10, (even if you have never crafted anything other than a tin spike!), and teach you to make items from all the different areas of expertise.
In addition to the tunic, you will also receive all the recipe books from 3 - 9 and a nice large bag. Over the course of the quest, the quest giver will also dole out enough cash for you to buy all the fuel and water you need to complete the quest.
And finally, he will let you keep all the items you make for him. You can sell them to an NPC or put them up for sale on the broker or even use them yourself, it's up to you.
The quest is worth doing for any character who is at all interested in crafting. It's both fun and rewarding!
Edited, Wed Dec 14 15:35:20 2005 by OldBlueDragon