Butterflies are in the hoop.
Actually this block is officially called "Beggar's Block", "Spool Block" or "Butterfly Spool Block"
I started making these 9 inch blocks a few years ago as a Rainbow Scrap Challenge project after I saw a vintage quilt that showed up in a google search of "vintage butterfly quilt".
And actually, the little 3 inch butterflies that make up the nine inch blocks are exactly the same block as the spools in the quilt top I showed last week.
I'm not marking anything but the butterflies for the centers.
I'm stitching inside each wing and all over the black body.