The technique of the present invention intermediates between an arbitrary client and an arbitrary printer connecting with a network to actualize practical printing works. A given transmit time interval will include numerous traffic symbols and two or more short pilot symbols, which are spaced apart from one another by at least one traffic symbol and will have a Fourier transform length that is less than the Fourier transform length of any given traffic symbol. A beam enters the single pass stretcher and is reflected in a helical path using the optical system for multiple passes through the single pass pulse stretcher. The gas-liquid separator is mounted in the separation chamber in the gas flow between the gas inlet and the gas outlet. The second sheet may be used to produce a particular appearance to the final image such as high gloss or a security pattern.