I believe that the ruler method is used in place of the mini bolt boards. For the mini bolt- you fold the fabric again (selvages to the factory fold edge)so that it measures about 11 inches wide. You start rolling/ folding the length of the fabric around the mini bolt until it is all wound on like the fabric bolts at the store but smaller. In the ruler method you use a 6 X 12 or longer ruler in place of the mini bolt board. The difference is when you have the fabric all folding/rolled around the ruler you carefully pull the ruler out and store the folded fabric on the shelf. Those who ruler fold, feel free to correct me if I'm wrong.