How to Paint on Cereal Boxes
- 1). Remove cereal box contents and cut open one long edge of the cereal box, so that it can lay flat. Whether you are painting the outside or inside of cereal boxes, laying the cereal box cardboard flat allows the paint to dry without running. Draw an outline of the design you plan to paint with a pencil.
- 2). Squeeze ample amounts of acrylic paint and acrylic medium onto a plastic palette. To paint the inside of the cereal box---which consists of an unfinished, absorbent surface similar to paper---thin your paint with medium as desired and paint your cereal box. Paint layers of color on the box inside to cover up the gray cardboard and to get vibrant results. To paint on the cereal box's existing design---which is coated with a water-resistant finish---dab your brush with acrylic paint without mixing it in thinning medium, and paint on top of the existing design.
- 3). Place painted cereal boxes on a clean surface free of dust and debris. Let your painted cereal boxes dry for at least three hours, depending on the thickness of your paint. If paint does not dry after three hours, let your painted cereal boxes dry overnight.
- 4). Lay the dry, painted cereal boxes on a flat surface and coat them with a layer of acrylic varnish for a shiny, finished look. Prepare acrylic varnish by mixing it with water according the the manufacturer's directions. Use a very clean or new brush. Leftover color in a used brush could activate when moistened and ruin your design. Apply a thin coat of varnish and let your cereal box dry for at least three hours or overnight.