A future project on Drawspace shows you how a softly rendered background can successfully separate a white subject from white paper. This is Wesley, the proud owner of my daughter Renée, and her husband Dave. The reference photo is not very clear, so I may have to do a little research on Maltese dogs.
First of all, I lightly sketch him on a 9 by 12 inch sheet of Arches, hot-pressed, 140 lb. watercolor paper. I then add a little light shading to the negative space on the right.