He is so white as to be almost transparent, and I thought it would be a good exercise in modeling with pale greys. I put my white-ist whites down first, just as I have done in the last few paintings ( with relative success)except this time I could not keep the whites clean. They disappeared into surrounding paint and I had to spend lots of time re-establishing those areas, and very soon I hated the dog and the white, and it took twice as long to get it done and over with. However - I learned about the temperature of whites! And that is what must make white shimmer, shifts in temperature from cool to warm in very close tones.