In addition to the vertical wires there are two horizontal wires running across the screen at one third and two thirds high. These serve to reduce the tendency of vertical wires to move. These wires can be seen on the screen of aperture grill displays as fine gray lines. Some more discriminating monitor users dislike this quality very much. On the plus side aperture grille displays provide excellent colors.
Shadow mask is a similar type of display.
This display works by using a metal or ceramic plate with holes to project the image onto the screen. Shadow mask displays are preferred for their straight lines and proportions. This display uses Twisted-Neumatic liquid crystals that are illuminated, thus creating the display. While LCDs are more expensive, they are growing in popularity due to the compact size of flat-screen displays and the lower amount of power they use. A fourth type is the gas plasma display, but I have opted not to explore this monitor assuming my readers are poor college students and lack the tens of thousands of dollars needed to purchase one of these monsters.