The natural green copper patina can be mimicked with an ammonia solution, while the slightly darker color of an American penny can be created with baking soda and water. Because the application of these solutions are so similar, they are both described in this section. Wipe the item clean with a dry cloth. Grimy copper items should be washed in warm, soapy water instead, then dried thoroughly. If you are trying to create a green patina, you'll need to use ammonia. Work outside or in an area with a powerful ventilation system or fan. Ammonia fumes can be toxic, so ammonia should never be handled in an enclosed space. Rubber gloves and safety glasses are recommended. If creating a brown patina with baking soda and water, no safety precautions are required. Stir together 2 cups (or 500 mL) white vinegar, 0.5 cups (or 125 mL) non-iodized salt, and 1.5 cups (or 375 mL) clear ammonia. Ammonia can be found at some grocery stores and drug stores, but take care not to purchase the weaker "detergent" variety. The more salt you add, the greener the patina will be. This solution will turn your copper a darker brown, roughly the color of an American penny. Simply shake baking soda in a bottle of hot water one spoonful at a time, until additional baking soda does not dissolve. Use a spray bottle to apply the patina onto the surface of the copper. Spray more heavily if you want a more even result rather than streaks or patterns. This patina may take a few hours to develop, but keeping it in moist air will speed this process up. If the copper is kept in a dry environment, use a plastic bag or plastic sheeting to cover the copper without touching its surface. This will help retain moisture. Depending on the environment the copper is kept in, and how often it is handled, the patina may wear off or fade before it sets permanently. If this occurs, reapply as before, either to the entire surface or to the area wear the patina has rubbed off. The green patina tends to be more powdery and easier to rub off than the brown one.
امزج محلولك الخاص لخلق ألوان معينة. نظف النحاس. اتبع إجراءات الأمان عند العمل مع الأمونيا. استخدم الأمونيا للحصول على زنجبار أخضر. امزج محلول اللون البني بدلا عن ذلك. رش النحاس بالمحلول. أبقها في  منطقة رطبة من ساعة لثمانِ ساعات. أعد وضع المحلول في حالة تلاشى اللون الزنجاري.