Because I knew from the beginning that this would not be a finished piece, I felt free to throw everything I had into the collage background - papers from dark to light, more photos in black and white and color, and also leaving parts of the background canvas exposed. The photo overlay is printed on a piece of art tissue cut to a size to fit my inkjet printer and sprayed with a fixative when the ink was dry. The piece is built on an 8"x8" canvas.
I had to be very careful when applying the tissue paper to the canvas as it is quite fragile when wet, but the tissue paper worked very well! I learned that I need to be much more careful with the placement of the parts of the collage as they relate to the photo - anything under a white part of the photo will show through almost too well, and papers that are too dark will blur details. Next time I will cut my collage pieces to exact size so that I don't get a ridge where the papers overlap, and also not leave any of the canvas exposed as it stands out like a sore thumb. Or a mistake, LOL.
My next experiment will be with tiling an image - I want to work larger than the 8"x10" size that my printer limits to. Getting closer...!