I have used this with the 5-year olds in our homeschool 'Around the World' co-op when we were covering Indonesia, on the topic of deforestation. We read 'The Great Kapok Tree' and talked about the animals that live in the rainforest that might be affected with deforestation.
This template was printed on A4 catridge paper (about 130gsm), and I got the children to trace the gray lines with white oil pastel. We then used watercolour to paint the animals and initial white lines drawn earlier will resist the paint. Crayon resist in action! :)