unwanted black background appears behind one image after submitting to lulu
I just submitted my first pdf to hulu. It includes a number of small black line drawings with white backgrounds. All came back fine except one, which is now embedded in a black box. The black background was not there in the original image, and it was not there when I converted the doc file to a pdf. The black background only appeared when I got my pdf back from lulu, and it only happened to one image. I have no idea why it happened or how to fix it.