Video: Large containers tend to have spouts on one side and it's a pretty natural reaction to attempt to pour that liquid just like you would with a small container, with the spout closer to the ground. As Tested points out, that's a recipe for a mess. With big, 4L cans or even 18L containers, you want to pour them out with the side of the spout higher up. This makes the liquid pour out nice and smoothly. If you work with large containers a lot, this is pretty obvious, but since most of us don't, it's a handy tip to remember next time we're trying to dump out that 4L can of acetone.