I have taped an embroidery design and the fabric to a window and then traced the design. Now I have a light box that DH made and it is much easier. I use a tiny size Micron pen but you could use anything, a pencil, what ever works for you. I trace the design on the main fabric and then baste a piece of muslin to the back before doing the embroidery. I am assuming you are talking about hand embriodery and not machine. You might Google your question and you will get good information, more detailed. Good luck.