Full color window graphics are great for reinforcing a brand or promoting a product or service. The eyes of passers-by are drawn to the advertising and it drives footfall into shops. Shoppers inside retain their view of the street and also benefit from privacy, shading, and reductions in solar heat gain, glare and UV radiation.
We would normally recommend a 30% transparency inside application to achieve the best balance between strength of image outside and the view out/daylight in from the inside.
Other transparencies should be considered depending on a number of factors including the brightness of sunlight and the nature of the retail space inside.