Wood and metal are durable materials capable of holding lasting messages. There are four main ways of writing on wood and metal, including painting, burning, engraving and etching with acid. Each of these has its benefits and drawbacks, but at least one is guaranteed to be suited to your experience level.
If you are working with kids on your printing project or if you are a novice, use stencils and paints, as these are much safer when compared to electrical tools, hot pens or acid. Wood-burning pens are the modern electric version of old branding irons, while electric metal etching pens mechanically scrape away the metal. These are more durable methods than stencils and paint. Acid etching chemically eats away at the surface of metal. Use this method only if you're familiar with how the acid acts and can handle it safely.
Make sure paints are nontoxic and quick drying. Familiarize yourself with how wood-burning tips work on scrap pieces of wood before you use your craft wood. Not all woods will handle the same way--you'll burn soft wood much faster than hard woods. The same rule applies for metal-etching pens, because different metals have different densities. If etching on metal with acid, use a ferric chloride-based etching solution that contains about 20 percent citric acid. This is much safer than some other acids used for metal etching, and the citric acid will keep sediment from forming in the acid solution by lowering the pH level.
To print using stencils, hold the stencil over the wood or metal and wipe your paint-filled paintbrush over the stencil. Don't put too much paint on the brush. When you remove the stencil, peel it up rather than sliding it off so that the lettering doesn't smear.
For wood burners, press the tip lightly over the surface of your wood for only a few seconds. The longer you hold the pen on the wood and the harder you press, the darker color (burn) you'll get. Wipe your tip often to remove the carbon buildup.
If etching metal with a pen, clean the metal thoroughly. If you warm the metal slightly and coat it lightly with oil, the danger of splintering is reduced. Don't press too hard or you may cause the pen to slip.
For acid etching, cover all of the metal you don't want etched with melted wax. Then scrape the words into the wax so the tip of the engraving tool just scratches the metal under the wax. Give the wax at least a few hours to harden before etching. Pour the acid into the etching and let it sit for at least 10 minutes. Rinse the work and carefully scrape away the wax.