Tru-Oil is designed to be used on wooden gun stocks, especially refinishing antique ones. It is also used to finish musical instruments such as mandolins and guitars.
Tru-Oil can be used on most wooden surfaces, so it is also used to finish wooden tool handles. It is made from a linseed oil base to moisturize and protect the wood. It is popular for items that are handled frequently because it has a reputation for being more resistant to wear than some other varnishes. It also does not dye or stain the wood, although it deepens the color, adds a shiny finish and makes the grain stand out more.
Tru-Oil does not work as well on oily woods such as cocobolo, although it can be thinned to help with the application. It also does not work with lacquer. It works best if applied in multiple coats, which also gives it a glossier finish. People who want a less glossy look can gently scratch the finish with an abrasive material.
One of the reasons it is popular for antique gun stocks in particular is that it does not significantly alter the appearance of the gun. However, vintage or antique gun owners should check to make sure refinishing their stocks does not reduce the value of the piece. Some collectible weapons are worth more in their original condition.