If a 'background-image' is specified, this property specifies the initial position on the X-axis of the background image specified in the browser window if it is not continuously tiled in the element's rendering box. A minimum value for this property indicates the left side of the rendering box, and a maximum value is at the right side. The Y-axis component of the background position can be specified using the 'background', 'background-position' or 'background-position-y' properties.
Â background-image: url(watermark.jpg);
Â background-position-x: center
Percentage is in reference to the dimensions of the box of the current element. Value specifies the percentage on BOTH the image and the canvas and may be negative (eg: 20% indicates the reference point 20% from the left side of the image is to be located at 20% from the left side of the element's rendering box
Represents an absolute X-coordinate position for the image and may be negative. Standard Absolute or Relative Length Units may be used here
Keywords representing X-axis screen positions for image placement