A finished slat for a window covering includes both the structures and process for producing covered slats. A skeletal structure optimally constructed from a material such as wood or plastic, manufactured to a thickness which is much less than that of conventional slats, yet which is strong enough to support both the skeletal structure and a decorative covering and is rigid enough to avoid warping or sagging over time. The decorative covering may be made from a wide variety of materials, thus creating an infinite range of decorating possibilities; further, the covering may be embellished with artwork or trim according to the tastes of the user. The covering may be closed together around the skeletal structure using any of a variety of techniques, such as heat welding, glue, ultrasonic bonding, stitching, or any combination thereof.