English: A graduated cylinder filled with various liquids to illustrate density. It's also really colorful and pretty. Same cylinder as File:Artsy density column.png, but this picture was taken before the bubbles settled out of the oil.

From the bottom to the top

0–11 ml Maple syrup
11–30 ml Gradient from Dish soap (green) to water (dyed blue)
30–34 ml Water (dyed blue) ^a
34–39 ml Wine (dyed red) ^a
39–49 ml Vegetable oil ^b
49 ml–top Olive oil ^b

^{a b} They sorta blend into each other.

Instructions for creation (what i did; may not be the most efficient)

1 Add maple syrup to an empty graduated cylinder; take care to avoid spilling it on the sides (I used a pipette for this).
2 Add one drop of blue food coloring to about 100 ml of water.
3 Pour in some of the blue water using a pipette if wanted (if you get it on the sides, let the cylinder dry after)
4 Pipette or pour in some dish soap, it should settle below the water without many bubbles, though it may form a gradient (which is pretty too.)
5 Use a pipette to suction off any soap bubbles that may have formed on the water surface.
6 Pour in vegetable oil
7 Pour in olive oil. The olive oil should float above the vegetable oil, but it may form a gradient. There will be bubbles in the oil; these should dissipate in a few hours.
8 Pipette in some more blue water—it should sink, and the oil will slow it down enough so it won't mix with the now turquoise soap-water gradient.
9 Add some red food coloring to some cooking alcohol.
10 Pipette in the alcohol; it should sink through the oil in a similar way and settle above the pure water layer. There may be a short purple transition zone.
11 Let the cylinder settle for two or three hours.

I didn't include any milk, but if you do, it should be somewhere between the water and vegetable oil. Be prepared to wait a few days for it to settle into a nice defined layer.