What's negative space you ask? It's the space around or between objects. One of the best illustrations of negative space is this famous image of a vase. There's the white vase and the black around it (Read below for fun facts.)
I was at a client's house the other day and we were rearranging furniture. We tried a lamp from one room on a table in a window. She had existing swag valances and the space made between the window frame, the swag and the cone-shaped shade was lovely. She wasn't sure what she thought about it but then I started talking about the negative space.
If you haven't thought of negative space before, look around your home. What is the space between objects and furniture like? What is the space around your art work like? Do you have sets of art hung together? How much blank space is there? What if you shifted it a bit? Would it be more dynamic?
Here's a visual of what I mean from my portfolio. The image was shot by Eric Roth. See the space around the pottery, between the pottery and the relationship between the mirror and the pottery? That's all negative space you are "seeing." You could almost cut it out and it would be a shape. Also making objects "kiss" like the two vases on the right can be very interesting.
Fun fact. The black and white vase image is also an optical illusion called figure-ground. The positive space — the white vase and the negative space — the black around it flip back and forth so that sometimes the black appears to be the positive space — two people in profile, facing each other. But I digress.