Lacis, net embroidery, and net darning all refer to the same process of filling in plain netting stitches with other threads.
Here is a bookmark made of square mesh 11 squares by 40 square.
Two small bears have been darned onto the bookmark.
Here is a sample that was used as lace on a blouse.
If you are interested in more information on lacis, net embroidery, or net darning, a list of links has been compiled for you.