Beady, I am going to be using fat quarters and will also be looking at my larger scraps. The book does suggest to have "a large variety of 100% cotton fabric in different colors and values. Large pieces pieces of fabrics are not needed". I would imagine anyone who plans to enlarge the blocks may have to consider larger pieces of fabric ?
For those who have concerns about black background have a look at google images as examples of other coloured backgrounds can be found.