摘要 |
<p>An ink composition for writing on an absorbent or pervious writing surface to form thereon a writing or marking composed of an inner portion of a first color with outer contour portions therearound of a second color, which composition comprises: a polar organic solvent, a nonpolar organic solvent which is miscible with the polar organic solvent, a first dyestuff which is soluble both in the polar organic solvent and a mixture of the polar organic solvent and the nonpolar organic solvent, but which is insoluble in the nonpolar organic solvent, and a second dyestuff which is soluble both in the nonpolar organic solvent and a mixture of the polar organic solvent and the nonpolar organic solvent, the second dyestuff being different in color from the first dye-stuff, whereby the first dyestuff forms in conjunction with the second dyestuff the inner portion of the first color based on the first and the second dyestuffs, and the second dyestuff forms the outer contour portions of the second color based on the second dyestuff around the inner portion.</p> |