The 2D board display options dialog allows to select the background from a default image - the green table -, an own image or a simple color. To select an own image, click the "Select image" button and point the file selector to your image. The following formats will be accepted: BMP, PNG, JPG and GIF. The images do not need to meet the same requirements as the OpenGL files, like a square size of a power of two. Square images will work best, but other sizes will work as well. If the image is smaller than the board window, it will be automatically tiled. Selecting very large images is not recommended.