Roller Pen are writing instruments which use ball point writing mechanisms with water-based liquid or gelled ink, as opposed to the oil-based viscous inks found in ballpoint pens. The characteristics of these less viscous inks, which tend to saturate more deeply and more widely into paper than other types of ink, give rollerball pens their distinctive writing qualities.

 Close up of an extra fine Roller Pen next to something written with it.The rollerball pen was initially designed to combine the convenience of a ballpoint pen with the smooth "wet ink" effect of a fountain pen. Gels usually contain pigments, while liquid inks are limited to dyestuffs, as pigments will sink down in liquid ink (sedimentation). It is the thickness and suspending power of gels that allows the use of pigments in gelled ink. Using pigments (the same pigments that are used in paint) yields a greater variety of brighter colors than is possible in liquid ink. Gels also allow for the use of heavier pigments with metallic or glitter effects, or opaque pastel pigments that can be seen on dark surfaces.

Writing with liquid ink pens cannot be seen on dark surfaces because inks containing dyes need a light colored, reflective background, because dyes do not reflect light by themselves, in the way that pigment particles do. Dye molecules absorb all but a particular wavelength of light, so light must pass through the ink and bounce off a reflective background in order for our eyes to see the color of the ink.

The news come from www.bossgoo.com

Roller Pen