Sun Paper

It isn't often that I suggest something expensive or fancy to do science with preschoolers, but this is one of the exceptions: Sun Print Paper. This is photosensitive paper allows you to keep a shadow more permanently.

Making shadows on this paper is easy but you have to be prepared.

There different companies that carry this paper and other similar papers. They are a bit pricy to it is best to be very familiar with the directions before opening the paper. Once exposed, the paper cannot be used again. 

Here's what you need:

A sunny day

Sun paper

A handful of objects

A small piece of cardboard or clip board

If it is at all windy, a piece of clear plastic like for an overhead projector

Find a flat spot and pick your objects. Plan how you want to lay them out as you can't move them once you start. 

When you have everything, put your sun paper on the cardboard upside down. Flip it right side up and place your objects. Wait for 1-5 minutes. The paper will fade to a light blue when it is finished developing. 

Turn the paper over and take it inside to finish.  Rinse the paper in water for one minute.

 Let the paper dry flat.

The paper will darken a bit as it dries. To make it completely flat, you can put the dry paper in a book for  few days. 

This paper is a blast to play with but it can be pricy if you mess it up. An alternative is to try non-fade resistant construction paper. You have to hunt for it,but dollar stores are a good bet. Place the objects on the paper but you have to leave them in place for most of a sunny afternoon. Then you can keep the shadows by putting up on a wall that is out of the sun. 

Have fun and get messy!