Conchalea - as to your thread, use what you like on the front, I can't remember what your top looked like. I like to sort of go mid value - that way it will look nice with light and dark. But then, using a white or very dark on the top is dramatic. As to the back, don't forget that if you are using a dark top thread and a light bottom thread, you will get little pops of light here and there on the top of the quilt. Not enough to be noticeable if your fabrics are busy but something to think about. Can't wait to see your results, and good luck!