As I have mentioned in previous posts, I really enjoy painting water. There are so many colors, reflections, and moods you can portray. Ice is another beast altogether. Even though I have always lived in northern climes, painting ice does not come as naturally for me.
When I paint whites, I start with titanium white. Most of the time I mix in a tiny amount of cadmium yellow deep to create a more natural white before I apply it to my board. In this case, I wanted a little bit cooler white for my pack ice. With a base of titanium white, I started by adding a smidgen of lemon yellow. To that mixture I added a teeny amount (these are very exact measurements) of cad. yellow deep. For the shadows in my pack ice I used mixtures of titanium white, viridian, paynes gray, and ultramarine blue.
I've now moved on to blocking in the water.