While this is under preschool, this is a good activity for any age. However it is exceptionally good for preschoolers for many reasons.
When painting the foil makes lots of lovely sounds, this is engaging for youngsters and encourages the learning of cause and effect. The paint also mixes well on the smooth surface showing how to make different colours, plus the shiny surface makes for a very interesting activity.
The boys love painting, but painting on tin foil is extra fun for them. They love the scrunching and crunching sounds and the shiny, smooth texture.
Why not give it a go? All you need is some kitchen foil and poster paint.