In addition to differentiating itself for the various forms adopted by the producers, the barrel has also undergone the evolution in the use of the [[materials]] used in the construction of the fountain pens, of which it constitutes the largest component. At the dawn of the fountain pens it was mainly made of [[hard rubber]] like the rest of the pen, a material that guaranteed, having to serve as an ink tank, the necessary chemical resistance. | In addition to differentiating itself for the various forms adopted by the producers, the barrel has also undergone the evolution in the use of the [[materials]] used in the construction of the fountain pens, of which it constitutes the largest component. At the dawn of the fountain pens it was mainly made of [[hard rubber]] like the rest of the pen, a material that guaranteed, having to serve as an ink tank, the necessary chemical resistance. |