The 'Higham Rocks' project, involving all 360 children at Higham Ferrers Junior School, aims to pass on positive messages and make the community a happier place. It was created as part of a mindfulness art week earlier this month.
People are encouraged to find the rocks and hide them again in different places in Higham for others to find them.
All of the rocks painted by pupils at the Saffron Road school are now in the town for people to find.
Robyn Foward, art co-ordinator and Year 6 teacher at Higham Ferrers Junior School, said: "The pupils have worked extremely hard researching and making positive messages and have shown perseverance on painting on such difficult surfaces to produce some wonderfulart work.
"The children are all on board and want to spread positivity in our community and get people outside and in nature.
"We hope other local schools and families will join us on our mission and help us in making our community a happy place to be."