A bit of bowl-lathered Czech & Speake Oxford & Cambridge. Looks like my technique could use some work. ;)
They're different colors because I don't have a full set of filters and had to use different colors to get the quantity of lighting right.
Fairly newly made
A bit later the bubbles start to collect into larger bubbles
scale 1mm divided into 100 divisions (Might be slightly off because it uses reflected lighting instead of transmitted lighting)
The difference in density between the two pictures is a lot more than it looks in a flat picture. Just think about how the difference also runs through the plane of the picture. You can see more stuff in the background in the first picture. The difference in the amount of light that came through those two was also drastically different--when I switched to the second picture, it was completely white because the light went through a whole lot fewer bubbles.