Thank you! I use acrylic ink. I have tried "liquid acrylics" (thinned acrylic paint) and found that it looked too painted on, as in it sat on top of the wood too much. Acrylic ink soaks into the wood a bit due to its watery consistency but still offers substantial opacity and I can still blend colors and create shading just like with paint. I have done pieces on much darker woods (walnut, sapele, jatoba) and still get vibrant color when I want it.
Yup, burned, basically just a variation of the "basket illusion" technique. Here's a closeup of the same piece:
number13-crop-2.jpg