Ink is either a paste or liquid formulated with dyes or pigments used to produce designs, texts, or images. Whether you’re using an ink pen or an industrial inkjet printer, the definition of ink is the same. Solvents, pigments, resins, dyes, solubilizers, lubricants, fluorescents, surfactants, and particulates make up the complex medium we know as ink.
As far as we know, ancient cultures as far back as 256 BC, ink has been used to create texts and drawings (images) just like today. The biggest difference is the technology that we have today compared to the basic tools like brushes and pen-like instruments they used in ancient times.
Inks are found in nearly every aspect of what humans do. For instance, it’s used to produce newspapers, books, and photos every single day. People use their printers to print out lists they put on their refrigerator and copy pictures to put on display in frames around the house.
In the manufacturing world, industrial inks are used for marking and coding on products across several industries. Look around your local grocery store and you’ll see several examples of marking and coding for expiration dates, sell by dates, and tracking numbers like UPCs.
Before the industrial revolution, making ink was an arduous process that was somewhat imperfect and limited. However, the basic process has stayed the same. Even with massive machines that do all the mixing and blending of black and colored inks, dyes, and pigments with oils, solvents, and other liquids, the basic concept of mixing dry pigments and colored inks is essentially the same.
Special recipes are used to manufacture industrial inks used for marking and coding. Carbon black is one of the dry pigments used to create black news ink, but it is also used in formulas that include petroleum oil, water, or soybean oil. Resins are added to the formula to help bind the pigment to whatever material being imprinted, which includes paper, cardboard, plastic, metal, and other materials.
These recipes aren’t much different than following a recipe for baking a cake or cookies, or for cooking meat and vegetables. Different inks and solvents produce different formulations, just like different recipe ingredients change the flavor of baked goods and meals.
When mixing carbon black dry pigments with oils or liquids involves something called dispersing that helps create an even blend of black ink. High-speed dispersing machines are used to efficiently disperse and chop dry pigment into really small, even particles that blend well with the oil or liquid to which it’s introduced in the formulation process.
Colored inks are different from dry pigments. Colored ink is made using water-based flushed pigments. No dispersing is required because this ink is already in liquid form unlike dry pigments such as carbon black.
There are still challenges to overcome when mixing colored inks, but that involves what it’s mixed with and what you want from the colored ink. The depth, vividness, boldness, and luster of colored ink is affected by how it’s mixed with varnishes, oils, and other extenders.
Industrial inks used for marking and coding are formulated in different ways to ensure that the ink can resist smudging and fading. The formulas are created for specific materials and applications to provide proper adherence and to meet legal compliance.