Cohler 18k Gold Pen Plating Solution 1oz. By Krohn Industries This is a 1 ounce bottle of specially formulated pen 14K yellow gold shade plating solution concentrate. This solution is specially formulated for use with pen plating systems that use felt tips. You can use this solution with the disposable pen plating pens with felt tips or with any make of pen plating system that uses felt tip plating pens. This is for professional use only. Be sure to soak fresh felt tips for several minutes before first use. Use a different felt tip for each shade of solution. Be careful not to contaminate felt tips or solution with dirt, grease or grime. Be sure surface to be plated is totally clean.