I just finished embroidering (by hand) the center of my latest crazy quilt. It was done with a single strand of silk floss (various manufacturers) and a #10 sharp needle. I used a fine line sharpy pen to trace the design onto the silk dupioni fabric. Then, I backed the fabric with interfacing to provide support, as I do not use a hoop when I embroider. I used a single strand of Bijoux metallic to outline the letters in CRAZY QUILT.
Here is a close up of the "C" with a penny next to it for scale. It was difficult to photograph, as the light bounces off of the silk fabric and silk embroidery threads. The color of the fabric is a periwinkle blue.
A photo showing the fine needle with a strand of silk floss.