Once the non essential "background" is eliminated, look closely at what is left. What you are going to have to do is decide what color is MISSING!!! Look for primary colors first... red, blue and green, computer wise. I usually pick green as skin tones are generally comprised of reds, yellows and blues and choosing black or white is going to put holes in all your shadows and highlights when we get to the point of making a transparency. This is why you needed to make the original "background" into and object or layer. After the MISSING color is chosen it will become the "new background" that you will flatten the object layer onto. Once you have made your choice, set your "paper" color and flatten the image or combine the objects with the background as Corel puts it.