I am often asked about the best way to keep stained glass clean and shiny......There are many answers - it will be up to you to decide. Stained Glass Panels are generally pretty hardy and the soldered copper foil tends to get a nice hue just letting it be. But, if you want your solder to shine, you will have to use something to compound the solder a little. I use Mr Clean Magic Erasers with a good glass cleaning compound. You can also use bronze wool or try buffing with a pot scrubber and compound. Start cleaning your piece with a good dish detergent if it will fit in your sink. If your glass piece is much larger than your sink, put a large terry towel or newspapers down and clean with a good window cleaner or ammonia. If your piece is clean enough for your liking just go ahead and hang it back up! If not, once you have the panel cleaned and dry, you will start with your glass compound. If you do not have any specific glass compound you can use regular ole car wax. I use Turtle Wax but most brands will do. This is going to take some of the oxidation off of the lead solder and also shine your glass. It is best to use an old terry washcloth or piece of towel to buff your glass. You will also want to be sure that if any foil is showing, be careful not to "disturb" it. Work around those areas carefully. Another thing to remember is not to press too hard on any glass that is laying down. I have learned the hard way that glass looks and acts very strong but will break with just the right pressure is applied. Especially small thin line pieces! After you have buffed and shined the piece with glass compound or wax, you will likely have dust residue left behind. Just use a paper towel with plain water to clean those areas of residue. Make sure to wipe the glass until completely dry with newspaper, paper towel or terry cloth to keep it from streaking and get the very best shine.