Why i cant sell some items?

Hello everyone! the thing is that im trying to sell some items, like blood bottles or bronze pieces, but the sistem dont let me do it.

There is some item i need, some exp anything o do it?

I mean i buy those things from other users! why i cant sell them?

Thanks!

Because some items are bound to your character and you can't sell them.

Buuu, and is there some way to brake that bound??? im sorry if the question is too silly, is the first online game i play :P

No there is no way to unbound items .

Ok! thanks!