When making Equipment with blacksmith if your inventory fills up to full and you keep using BS skill it will use all your materials and not give you any item as you have no room in inventory
It is not quite as simple as checking to see if you have room in your inventory.
The process consumes items and makes items.
The items consumed may be stacked and so their consumption may or may not create space.
The items manufactured may or may not be stackable and their may or may not be a stack already in existence and that stack may or may not have room available.
Heh all good wish I would of noticed month or 2 ago...cant imagine how many materials and gold I wasted when I was making 100peices of armor at one time lol