Starting in the very center of the scarf, sew across the width. When you reach the edge, sew three back stitches and then three forward stiches to reach the edge again. Carefully turn the scarf and sew ½” along the edge. Turn the scarf again and sew across the width in the other direction.
Repeat this process until you have sewn down to the end of the Solvy. Repeat on the other side of the scarf until you have reached the second end of Solvy.
As you sew, some pins might fall out and the yarns might become loose and tangled; this is okay. Just hold the scarf up and comb the yarns with your fingers, tugging on any that might be sticking out.