Window Sign are very effective for business to use and grow their business. Window graphics can be made from vinyl, printed vinyl, window perf, and even etched glass appearance.
This example is an upscale hair salon that wanted to have their logo prominent as customers walk-in to shop. They considered a etched silver vinyl but chose a gold etched vinyl instead. The clear glass has a nice logo view from the front and rear.
The window sign outside can be quite a large variety based upon customer need. Some examples of window perf
allow the customer to see a large graphic but the folks in the store can see outside. This is also popular on vehicle graphics. In this case a jewelry store chose to promote a top selling brand.
Another example of silver etched vinyl used on doors and window is shown here.
The door vinyl really looks nice and can help branding at a property.
Cut vinyl in various colors is shown below. Multi-color vinyl adds a lot to the design. The vinyl can be removed at any time and go back to blank window.
The common use of vinyl on the window looks custom and unique. Many brands use the windows for promotional purposes and long term use. 
Window washers may want to wash the letters carefully as not cause something to curl. Interior window signs can also be used. Hang a nice sign on the inside of the window. No one can peel or touch the graphic.
