I practiced using 11 1/2 block to start with and it was "almost" right for 12.5 but not quite so I looked thru my patterns and found one that used 4 1/2" blocks, 3 rows to make a 12.5 and had the 2 1/2" x 4 1/2" rectangles so instead of making an hourglass and then cutting it I just made it using a combination of patterns.... I also made one but I think the darker and white is much better than the lighter and white. Thanks for all the suggestions! I will definitely make the disappearing hour glass using the 10" blocks like in the video some day! Not sure what size it turns out but if its ALL the same size it wont matter