This is useful on servers to hide your valuables or have a secret mine or whatever you wanna hide :). The painting door is one of the most well known hidden doors in Minecraft. Start with a 2x1 doorway (the wall size doesn't matter, it just has to be at least as big as this wall). [1/3] To make a hidden door behind a painting, the first step is to punch a door-shaped hole into a wall. [2/3] Next, you need to put two signs inside the doorway to hang the painting on. Signs are used as they allow enough room for you to walk through the doorway. As such, players are likely to check for secret passages even if they are not trying to invade or thieve. As such, players are likely to check for secret passages even if they are not trying to invade or thieve.