Swiss Cheese?

"Instead of worrying about what you cannot control, shift your energy to what you can create." Roy Bennett

It seems kind of appropriate that my supermarket flyer collage looks a lot like swiss cheese now.  

I drew the circles with a white Posca paint pen then colored in all the negative space. Since there was quite a lot of white in the images I defined the edges of the circles with just a regular pencil hoping it would create a shadow effect.  

This was before.....

And this was after without the cropping....the margins are a mess because that's where I primed the paint pen to get it to flow.