Giant art mural - grades 2, 3, 4, 5 and 6

Inspired by this post, I decided to create a large, op art mural in my classroom that all of my art classes could work on. I had a bulletin board space in my room that wasn't being used to it's full potential, so I covered it up and got to work!

I first started with a layer of old construction paper, just to protect my bulletin board from the Sharpie that we would eventually be using. Then, I used large sheets of white paper to create the background, and started the outline of the optical illusion.

 Continue that way until the whole board is covered (I didn't manage to get a picture of it all covered before kids started coloring!)

The next step is to separate the sections checkerboard style. Mark every second section with an X in pencil (I had some grade 6 students do this for me.)

(Again, couldn't get a photo before those coloring hands got in!)

The idea was that kids could color ANY square that was white, in any color. If there was an X, it meant they left it blank. 

There were DEFINITELY some kids that accidentally colored in spaces with an X, but it wasn't really a big deal. Most of the time they realized after a few marker strokes, but also, during the next step, we were able to fix any mistakes.

Once all of the colored parts were colored in, students took Sharpies and colored in the spots with an X. This is where we fixed any mistakes - any of the X spots that had been accidentally colored were now covered in Sharpie, so you couldn't even tell that there had been color there before. And here is the final product!

 Here's a picture of it beside the wall - I did this so you can get a feel for how big it is. The soap dispenser is off to the left of it.

The kids REALLY love it! Every time an art class comes through, the kids always stare and talk about it. Kids have brought their parent in to see it. They all seem to love that they had a part in the completion of this mural. It was great that everyone from 2nd grade students to 6th grade students were able to help.

Has anyone else ever done a large collaborative mural?