Arcane Carving

Using your finger (or other object you can hold in your hand), you can imprint a small image onto a nonliving and nonmagical surface. You choose what you wish to imprint (shapes, a message, etc.), and the size of your image cannot be more than a square foot in diameter. You decide the color(s) of your image, and, although it doesn't shed any light, it glows faintly and can be seen in dark and dim light, including magical darkness. You can only create one image at a time, and you can will the image to disappear at any time (1 bonus action) no matter where you are or how far away you are from it (unless you are prevented from using magic in some way). The image cannot be destroyed by nonmagical means, but using magic on it in any way causes it to disappear. Until the image is dispelled by you, destroyed with magic, or until you die, the image lasts forever.