Guild Wars 2

Is it possible to transfer the backpack you bought from the black lion market from character to character?

Probably not directly, unless you have it on an Ascended back item. However, the skin is in your wardrobe once unlocked and can be used by any or all of your characters for one transmutation charge.

Garambola.2461:

Probably not directly, unless you have it on an Ascended back item. However, the skin is in your wardrobe once unlocked and can be used by any or all of your characters for one transmutation charge.

I thought transmutation charge is zero because I used one and it said zero ;-;

The first application of a skin is free, the skin carries a charge so to speak. Applying from the wardrobe costs a charge per use except on some special items.

This means my bank is clogged with unassigned skins because I don’t want to burn up the transmutes just to put them in the wardrobe ><

A skin that you have in your inventory won’t need a charge, but a skin that is only in your wardrobe will cost you a charge.

Unless the skin is from the Hall of Monuments, or Zenith/Pinnacle weapon, or an outfit. Those are all free forever.