there are many bowls on thingiverse, but since I am learning Blender, I did this and I like the result, I'm sharing it. it's a 15cm bowl, feel free to scale :)
17.Feb 2017: 8 more designs. Check out the rendered image of all bowls, choose your number and download corresponding file :)
14.Apr: Thanks Noneus for reporting a glitch in no. 1 and 2, fixed!
Print in corkscrew spiral mode and set Top Solid Layers to zero. Models are ready to print using Vase mode, no modification needed
I have used PLA and PET. the PET version is pretty much flexible, may be better choice to use PET