As an inspiration point the students had already listened to the book "Snowmen at Night" by Caralyn Buehner. In this book the snowmen are illustrated with beautifully rendered orange and blue tints to give them a round appearance. This was the look we were going for and what I needed to help the students achieve to an extent.
So, rather than just keep going with the snowmen paintings as they were, I reminded the students that the great thing about paint (tempera in this case) was that once it was dry you could always paint over it to rework something that wasn't quite where you wanted it to be -- such as their snowmen. They all agreed that they needed some more help with the concept of tinting and were happy to paint back over their existing work.
My demonstration snowmanThe demonstration I gave focused on the use of wet-in-wet painting techniques, which was the opposite of what they had been using. They had been mixing their tints separately and then applying the paint. I showed them how to start with an all white snowman shape and add just little bits of color at a time using the direction of the brush stroke while blending the tint to create the roundness of the form. They were impressed enough at the result to give their own paintings another try. While there is still room for improvement the comparative results from how they first looked are astounding. Several students were able to get their tints to seem less stark and even to achieve some roundness to the form. Below are a few examples:
Now, since the students reworked their previous attempts, for the most part they did not get beyond making just the snowmen. But I thought it would be nice to leave a completed example for the regular art teacher along with some notes on my ideas for the assignment. I envisioned the snowmen interacting in some way with details added with colored pencil. And the ground would be painted white. While the paint was still wet, I sprinkled iridescent glitter onto it to give it a little sparkle like new fallen snow. I also included in the note that if he tried this assignment with another class, I would do several practice sphere paintings using white and the tinting colors before attempting the snowmen. The students would benefit from the practice and feel a greater sense of accomplishment with the final project if they could "play" with the idea first.