Pen ink is made from dyes that are suspended or dissolved in solvents, making it very similar to paint. The first inks were vegetable or fruit juices and the protective secretions from squid, octopus and cuttlefish. Blac... More »

Modern printing inks are made with oils or petroleum distillates combined with organic pigments. Black ink is made with carbon nanotubes. More traditional inks are made with a mixture of dye and oil or water. More »

Dating back to Neolithic China, India ink is a deep-black ink made from carbon sources, such as soot, mixed with water. Additives change the durability and consistency of the product, so some manufacturers add glue or sh... More » Hobbies & Games Crafting

Pen ink is not usually harmful to skin. Pen ink is not usually poisonous in small amounts because it is made from a mixture of dyes, pigments, solvents, and alcohol or water. However, it can be toxic when ingested. More »

Thousands of products are made with coal or coal by-products, including aspirins, soap, dyes, solvents, plastics, and fibers such as rayon or nylon. Coal is an important ingredient in production of products that require ... More »

The body of a retractable pen houses an ink tube held in place by a spring at the pen tip and a retraction mechanism at the other end. There are several types of retraction mechanisms that allow the user to toggle betwee... More »

To use a gold testing pen, hold the pen wire under the test metal, rub the point of the pen's tip onto the top of the metal, let the gold metal dissolve into an ink onto the tip of the pen, and use the ink to draw a line... More » Science Earth Science