You HAVE to see this.

The optical illusion site I go to has an amazing post today.  Using threads and beading for installation art.

Rug illusion

As I have mentioned before, I am interested in optical illusions and I have a site that comes automatically to my home page.  This one was of particular interest. It is of a rug that has been woven to look as if it has a lower level.
Maybe I should put the link on my sidebar.