Some say 1 part glue to 4 parts shaving cream and some say equal amounts of each.
I used 1 part pva glue and 4 parts shaving cream, as the glue can be quite expensive, so I didn’t want to use too much of it up.
This worked great, and then I separated the glue/shaving cream mixture into small containers and added a few drops of food colouring to each to colour it. The boys preferred the colours to the white as they wanted to paint things, but were having trouble coming up with white things that they wanted.
They used paintbrushes and painted on an open manilla folder as the paint just went through the normal paper. It needed something thicker.
Here are some links to other people’s snow paintings