Most of my fabric (and other) designs are based on textiles or art from the Middle Ages or Renaissance, but sometimes I do reproductions of stuff from the 1800s. Like this:
I just made this design this morning.
A customer contacted me by email, asking if I could make a reproduction of the fabric from a dress on display in the museum where she works. She sent me two high-resolution photographs so I could really see the pattern and get an accurate idea of both scale and colors. A few hours later… ta-da!