Cardboard is one of the most versatile products ever used in crafting. It's easily cut, bent and shaped to create whatever piece is needed. Recycling cardboard also helps make the world a little greener. Cardboard is plentiful and many stores allow you to take cardboard boxes rather than destroying them or sending them to the baler. Some business establishments do recycle their own cardboard.
Liquid Acrylics and Latex
Liquid acrylic craft paints are the most popular paints used on cardboard. Several brands are available at most craft supply shops. They are sold in 1- and 2-ounce bottles and are a water-based paint. It can be cleaned off easily or painted over when is used on cardboard. Acrylic craft paints become permanent when they're allowed to dry on fabric. Gloss, semi-gloss and flat paints are available. Leftover latex interior wall paints can be used on cardboard. Place the leftover paint in glass jars with tight-fitting lids to use in painting cardboard and other craft projects.
Poster Paint and Watercolors
Poster paints cover cardboard well but they are flat paints. If a gloss is needed, cardboard painted with poster paints can be sprayed or brushed with varnish after the paint dries. Poster paint colors are deep and true so only one coat is usually needed. Watercolors used on cardboard may seem translucent but can be used in small areas that only need a little color. Tube watercolors can be mixed with water to make a darker color that is similar to liquid acrylics.
Color Markers, Crayons and Ink
Color markers work well on cardboard. Apply ink in perfectly straight lines or in small circular motions to avoid the lines usually seen in some artwork. Permanent or nonpermanent ink markers can be used. Use a spray fixative, light varnish or clear coat to preserve the colors. Crayons are another option. Use straight, even strokes or circular motions to avoid lines. Apply inks with a brush or calligraphy pens.
Chalk, Pastels, Color Pencils and Other Items
Using chalks, pastels and color pencils usually gives a much lighter color than paints or markers. The hue of pastels may be darker than chalk. Color pencil marks are lighter but can be darkened by wetting the tip of the pencil as it is being used. Nail polish colors can be used for small areas, quick touchups or highlights. Use aerosol spray paints mostly for backgrounds, especially in the case of painting signs on cardboard. You can also use lettering stencils with spray paint.