One time I urgently needed to draw a charge, and at hand, no needle to scratch or ruling pen, although the lacquer was. Then decided to fill them inscribed with the rod of a ballpoint pen. Rinsed it, squeezed out of the wire ball filled (though with difficulty) varnish – track was surprisingly smooth. Further recording head moved in a glass pipe length 10 cm, ppotiv rubber ring. Easier to fill, but draws like a technical pen, not overjoyed.
E. HELBLING, Donetsk