We started by blobbing on some paint with squirt bottles. I prepared five different colors and encouraged students to overlap colors to create new mixtures. We folded a piece of 9"x12" drawing paper in half before we painted and I had them paint only one side. After squirting on some paint and getting it all messy looking (by far the student's favorite part) we folded it together and opened it up to see what we had created. I talked with the students about what the folding had done to our painting. We discussed symmetry and what it meant along with things that are symmetrical.
In the next class, I introduced what we were doing by asking if anyone had ever laid out in the summer and looked up at the clouds. I asked if they had ever seen any clouds that looked like animals or other things that we recognized. I asked them if the clouds actually really looked like those things or if they just reminded them of what we already knew. We talked about how our brains work, how they take new information and relate it to things that we already know. This is how we learn and process new information. I then gave a demonstration using my own blob painting and asked students what they saw in mine. We came up with about 10-15 different things and I chose a few of the stranger images and outlined them in sharpie. We talked about identifying an image within the paint or using the entire painted area as am image. We also talked about positive and negative space, especially since some of the most interesting shapes were in our unpainted white negative space. I allowed students to choose what they wanted to outline in their paintings and before they outlined we passed them around our tables and helped each other identify things.