When cleaning windows it's not always what you see is what you get! Some window cleaning chemicals won't leave streaks right away but after a good drying period a dull film will start to appear. This usually occurs if the window cleaning solution has added chemicals that won't evaporate and are left as a residue on the glass. When purchasing a good window cleaning chemical or solution it is usually best to purchase products that are ammonia based. Ammonia based products will evaporate quickly and not leave any residue. Concentrated glass cleaners are great for use in climates where the temperature changes, especially if you are using them outdoors. A concentrated glass cleaner can be diluted with the correct amount of water for the amount of moisture in the air and the ambient temperature. Mix in more water for hot and dry climates and less water for cooler moist climates. By using this method you can really cut down on those window streaks. Another good tool to use when cleaning windows is a window squeegee. Window squeegees don't leave lint and can quickly remove any cleaning solution from your glass. Window squeegees come in many sizes and styles. For residential window cleaning a disposable window squeegee is the way to go. Disposable window squeegees do a great job and are very economical. When the rubber squeegee blade starts to break down and disintegrate just throw it away, and purchase a new one. Professional window cleaners and janitorial personal are likely to use a professional window squeegee with a replaceable squeegee blade. On these types of squeegees when the rubber blade starts to disintegrate you can just replace the rubber, retaining the original handle and channel. Professional window squeegee handles are made from many different materials such as stainless steel, plastic and brass. Brass will usually hold up better than other materials and won't rust. Window squeegees come in many sizes ranging from 12 inches to four feet. Some companies have tried to produce window squeegees over four feet but they are too hard to control and are too heavy for one person to use. Most professional window squeegees come in three sections, the squeegee handle, the squeegee channel, and the squeegee blade. Window washers are great for cleaning stains on windows such as bugs, bird droppings, and tar. Window washers are basically a semi abrasive towel attached to a handle and shaped like a window squeegee. The pad or towel on a window washer is usually made from cotton enclosed in a nylon net. The nylon netting is made to quickly remove the toughest of stains.