Screen printing consists of five major elements: screen printing plates, squeegee blades, inks, printing stations, and substrates. The basic principle of screen printing is printing by utilizing the principle that the graphical part of the mesh of screen printing plates penetrates inks while the non-graphical part does not penetrate ink. During printing, ink is poured onto one end of the screen printing plate, and squeegee blades forces a certain pressure on the ink portion of the screen printing plate while moving toward the other end of the screen printing plate. The ink is pushed by the squeegee from the mesh of the graphic portion onto the substrate during the movement.
History of signal flag
As early as the end of the 18th century, the signal flag was widely used by countries as an important means of communication for warships and merchant ships. Nowadays, the flag is still being used as the easiest and most reliable means of communication on warships and merchant ships equipped with advanced communications equipment such as VHF radiotelephones, Global Maritime Distress and Safety System (GMDSS), and satellite phones.