A printing control method of generating dot data representing a state of dot formation at each pixel in a printed image represented by an given image data, by formation of dots in respective pixels with the at least one colored ink and the quality-enhancing ink available in the print unit. The apparatus includes a network interface and a processor that selects the first signal source by outputting the address of the first server to the network interface, thereby establishing a network connection. The portable medical gas system is place in a specialized container having a configuration adapted to hold the portable medical gas system only when the cylinder of portable medical gas system is unused state or empty state. 35 gcm3 or lower, an amount of surface functional groups, OC value, of 0 or larger and 0.