If you’ve ever driven past a property and noticed a purple stripe painted on a tree or fence post, you might’ve been curious—or even a little confused. That stripe isn’t just for decoration; in many states, it’s a serious warning. Known as the “purple paint law,” it allows property owners to mark boundaries and signal “No Trespassing” without using traditional signs.
These markings are especially useful because signs can wear out, fall off, or be stolen, while a splash of paint stays put much longer. Typically placed three to five feet off the ground, these purple lines are easy to spot and make it clear that the land is private. While purple is most common, some states use different colors like blue or orange, so it’s important to check local laws before assuming.