Q:
Light, Medium & Heavy Costumes?
Under the style tab in the TP there are town clothes and armor skins; the description will tell you which one. The town clothes can be worn by any character, are accountbound, and last forever. These are worn outside of combat. That means you can buy the witch costume and wear it on one character, then pop it in your bank and use it on an alt later. The armor skins replace the look of a piece of armor, as if you were transmuting it. You can only use the heavy armor skin on heavy armor, which is why your guardian can only use the one.