A gap between two adjacent cubes should not exceed 0.3 mm per screen, which leads to a gap between two adjacent screens of about 0.68 mm. Then the gap can hardly be seen by the users and we can speak about a seamless display. A smaller gap between the cubes is not possible because of the screen characteristics. It can also be dangerous for the quality of the large screen system. The screen is sensitive to temperature and humidity variations, so in general those systems should be operated in stable environmental conditions (air-conditioned). If, for example, the air-conditioning fails, this can cause a growing or shrinking of the screen; a gap is required to accept these variations. Also it is important that these screens are fixed with flexible springs that can accept those variations. Some vendors offer fixed solutions; this is not ideal because the variations cannot be accepted with such a solution. A gap that is too small and unable to accept the variation in the size of the screen can cause the screen to shape like a bow. Not only will this create a distorted image, but there is a risk that the screen may fall out. Such phenomenon will not occur when the screen is operated in stable climatic conditions with stable air-conditioning.