In order to better prepare for my first developmental biology exam, I decided I should paint one of the diagrams on my nails, and neurulation seemed to be a fairly simple concept. The diagram I was going off of was one in a handout the professor gave us, but this one is close enough:
It turns out that the way I painted them (with the smallest, skinniest stage on the smallest nail) makes it rather difficult to get a picture of them looking like they're "in order" for the sequence, so I gave up on that and just photographed them this way.
And here's a cross section of the ectoderm, neural tube, mesoderm, and endoderm. The design ended up looking a lot more shaky than I'd hoped, probably because I used a dotting tool to draw the entire thing.
I don't remember exactly which colors I used, as I had a whole range out experimenting with which ones looked best, but I know the blue is from Cosmetic Arts, the teal is China Glaze Four Leaf Clover, and the white is Sinful Colors.