Abstract: A process for producing a sponge rubber stamp having open cell of the present invention comprises the steps of superposing an unvulcanized rubber sheet (A) containing a water-easily soluble powder upon an unvulcanized rubber sheet (B) containing an acid-soluble powder, heating/pressing them to form an integral laminate, treating the integral laminate with water to make the layer (A) porous, sculpturing the surface of the layer (B) of the integral laminate by a laser beam to form a stamp surface thereon, and then treating the integral laminate with an aqueous acid solution. No microcracks occur in the stamp at the formation of the stamp surface, and the stamp surface precision and the durability of the obtained stamp are excellent. In addition, the formation of a prototype and a matrix of the stamp as well as the treatment of the stamp can be simplified.

Abstract: A stick-like writing nib, made of a synthetic resin, has a plurality of narrow slit-like first ink passages extending radially from the axis in sectional profile and a plurality of narrow slit-like second ink passages provided in sector-like areas in sectional profile defined by walls the first ink passage, which are defined by a plurality of walls extending parallel to a line bisecting an angle subtended by the sector-like area into two angels, and inner end portions of the first ink passages being defined by thin walls extending along the nib axis.