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. Due to the stickiness of the ink, the imprinting is fixed within a certain range. During the printing process, the squeegee blade is always in line contact with the screen printing plate and the substrate, and the contact line moves with the squeegee.
If know the call sign of the opposite ship, firstly hang out the call sign of the receiving ship, and then hang the signal code block of about the message to be conveyed (if weather permits, it is also possible to hang out all at once).
Completion of communication: After the sending flag falls down the last group of signal flags, and shows all answering flags, it means the finish of signal sending. After receiving ship notices that, it will show all the answering flags to indicate that all the messages have been received, and then lower their respective flags.