1. Tape the curtain into place where you would like the pattern to be. Cut it to size if desired.
2. Spray over the lace with the white paint. Remove it carefully, don't let it dry so much that it sticks to your chair. When you remove it you will see that the original color of the chair shows through where it was covered by the lace.
3. Hand paint edges and add some color if you wish to neaten your design. In the images below a small amount of turquoise colored paint has been used to define the design.
4. Paint the rest of the chair white.