To work poster pens are very convenient, and who was fine — what makes them miracles: you can always pick up the desired width of the line, replacing the pen on the right more. But each can hold only one “track”. But this small improvement allows us to obtain two parallel lines… in a single pass. For this, needle files propisyvaetsya portion of the working edge of the Pera: are formed like two pens in one.
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