The potential uses and advantages of adjustable light shutters and reflectors based on reversible electroplating on transparent, chemically inert electrodes are indicated briefly. Over the entire visible light range, the highest ratio of optical density change δ to applied charge density appears to be achievable with Ag, especially when formed in conjunction with or ions. An aqueous plating solution containing 3–3.5M AgI and 7M NaI appears to be most suitable for achieving (a) a maximum ratio; (b) a satisfactorily uniform plating; (c) a maximum plating speed; and (d) a maximum rate of unplating. Of several electrode geometries and electrode arrangements capable of yielding essentially uniform plating, those utilizing adjacent subelements composed of parallel, closely spaced, flat, and narrow transparent electrode strips with line‐symmetrically situated contacts is preferred, especially for large‐area modulators. A series connection between the subelements is especially desirable.With aqueous electrolyte solutions, the shortest practical plating time must exceed sec, where is the electrolyte resistivity in ohm‐cm, and is in coul/cm2. Hence, to achieve both a maximal speed and a high δ, it is necessary to use several plating cells back‐to‐back. To maintain the desired opacity, a low, continuous plating current may be required, following the initial plating pulse. The time required to clear the cell may vary from less than a msec, in cases where a fast plating pulse is followed instantly by a rapid unplating pulse, to a maximum of (where a is the electrode spacing, and is the diffusion coefficient of the main oxidizing component, e.g., ) in cases where the plating is to be maintained for a long period of time prior to the application of the clearing pulse.