I've been thinking about it for a long time, that why TLG put some parts (rubber bands, capes, rubber moulded heads, etc.) into small plastic bags and/or tiny white boxes? I can understand the case of capes to not to get scratched, but what about the others? And those who store their sets in zip lock bags, what do you do with them? Put them in the bag too, or store somewhere else?

I think it's probably easier for machines to sort.  They are also probably sourced from different locations, and it's easier to keep those pieces separated if they're in their own bags, but I don't really know - it's all just conjecture on my part.

To answer your other question, the bags are great for keeping the set together, but then they typically go into box (I use those "bankers boxes" a lot, as well as for my instructions), or sometimes into the plastic "shoe box" size (6qt) containers when they are small enough to fit a whole set (or multiple sets).

I would think it's either to stop those parts damaging others e.g. to stop metal train axles from scratching other parts, or to stop those parts being damaged.

 

Thanks guys!

All plastic parts in separate bags I ever seen was produced in China. But not all parts that produced in China comes in separate bags.

I’d assumed that the separately packaged parts were that way to assist with the automated packaging process. Strings, rubber bands, cloth and the like are more likely to get stuck in a machine. The small boxes will pass through very much like the ABS pieces.