Abstract: The invention relates to a ball-point writing instrument capable of writing with an intense colored or black line which is easily visible and readable and as permanent and eventually non-erasable as the best customary ball-pen ink traces, but which, in addition, is easily erasable by mechanical means for an initial period of about two to four hours as a normal graphite pencil trace, without the use of bleaches or chemicals. These properties are attained by the provision of a novel ink composition containing stated rubbers and volatile solvents which control erasability.

Abstract: A method of increasing the resistance of delicate, elongated objects made of polymeric compositions, to fracturing, shattering, and splintering during application of stress forces during cutting, shearing or grinding, thereby permitting the formation of shorter finished objects with appropriately and smoothly contured ends from a long stock object. Differently stated, the present invention relates to a method of preparing an elongated, rod-like object composed of several plastic, polymeric compositions, having channels formed therein and extending longitudinally thereof, for subsequent cutting of such long object into short lengths with desirably shaped end surfaces.