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Claim 1

A WRITING COMPOSITION WHICH SIMULATES THE MARKINGS OF A CONVENTIONAL PENCIL LEAD CONSISTING ESSENTIALLY OF A STABLE COLLOIDAL DISPERSION OF GRAPHITE PARTICLES IN A LIGHT PETROLEUM OIL WITH SUBSTANTIALLY ALL OF THE GRAPHITE PARTICLES BEING LESS THAN 7 MICRONS IN SIZE AS THE PIGMENT AND SAID GRAPHITE PARTICLES BEING FROM 10% TO 25% BY WEIGHT OF THE WRITING COMPOSITION, A CARRIER COMPRISING A TAR-LIKE SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF TAR DERIVED FROM PETROLEUM AND BITUMINUOUS DISTILLATE RESIDUE AND ASPHALT DISSOLVED IN A PETROLEUM THINNER AND OIL, SAID COLLOIDAL DISPERSION BEING FROM 60% TO 80% BY VOLUME OF THE WRITING COMPOSITION AND SAID CARRIER BEING FROM 20% TO 40% BY VOLUME OF SAID WRITING COMPOSITION TO AND SAID TAR-LIKE SUBSTANCE BEING FROM ABOUT 16% TO 32% BY VOLUME OF SAID WRITING COMPOSITION, AND ADDING TO SAID COMPOSITION FROM ABOUT 5% TO 30% BY VOLUME OF A REFINED PARAFFIN BASE NON-DETERGENT TYPE MINERAL OIL WHEREBY THE WRITING COMPOSITION CAN BE CONTROLLED BETWEEN ONE WHICH REMAINS SUBSTANTIALLY ON THE SURFACE AND IS RELATIVELY ERASABLE AND ONE WHICH PENETRATES THE SURFACE AND IS RELATIVELY UNERASABLE