Painting stones with kids makes for the loveliest chaos, and with a bit of prep that chaos stays limited to the paint. Here's an afternoon that works, from table to drying rack.
Cover the table
An old tablecloth or piece of cardboard under the stones prevents stained tables and cross looks. Aprons or old T-shirts as painting shirts work better than you'd think.
Pick the right stones
Big, smooth stones are easiest for small hands. Wash them beforehand and let them dry fully, or the paint slides off before it's dry.
A white base coat saves time
A thin layer of white acrylic as a base makes colours pop and covers the stone faster. For toddlers and preschoolers this is almost ready to decorate on its own.
For the youngest ones
Finger paint or thick brushes with a short handle work best. Don't think perfect drawings, think dots, stripes and handprints: that's exactly what a kid loves most.
For slightly older kids
Cotton buds make neat dots for flowers or ladybirds, and a pencil sketch beforehand draws the lines they colour in afterwards.
Don't forget the ID
Let every child register their own stone in the app, with help of course. Writing the ID on it and hiding it is just as exciting as the painting itself.
Let it dry, then varnish
Give the paint at least an hour and only varnish once the stone feels completely dry. After that, kids get to choose where their stone goes.
