Thanks very much, larsgerrits! It works like a charm for the items. I think I finally understand these concepts. One more problem, though. I did the same thing with the blocks, and they work just fine while in rendering in inventory, or dropped on the floor, or, whatever, item form - but it seems that the blocks already placed (block form) won't change immediately; I did some testing, and it seems that they will all change together only when one of the blocks receives a block update, or when a previously hidden block becomes visible. The ones on the screen from the start, even if you look away and look back, won't change the texture until them, even if the ones in the inventory are already different. There seem to be some sort of buffer or cache for the block's texture, in order to make rendering faster, I guess. Is there a way to clear this buffer? I couldn't find any reference to it in the block class. I could iterate through the world until I found an instance of the block, and then sen an update to it, but that seems way too slow (and ugly) to me, and I'm not even sure it'd work, anyway.