This is the back side of the background. (I have distorted the background color to enhance the pencil markings.) I place the pattern upside down on a large lightbox. I then place the background block fabric upside down on top of the pattern. Using a very soft pencil (such as #4), I mark the back of the block. The soft lead markings do not last long, but rub off easily.
See next block for the following step.