ink-ballIt is slightly hard for our modern sensibilities to take, but we cannot avoid the knowledge that early printing houses reeked of urine. The ink was applied to the type by a couple of ink balls. These were leather-covered pads, and in order to keep them supple they were stored overnight in a bath of urine. Urine was also handy for cleaning off excess ink. An ink ball is illustrated at the left, and their use shown below. You can also see ink balls in operation in the video at my recent post Printing on a Gutenberg press.

300px-Chodowiecki_Basedow_Tafel_21_c_Z

 

 

 

 

 

 

 

Ink for writing with a pen would be water-based, while for printing it evolved to be oil-based. In the early day of printing, printers made their own inks with lampblack or soot and animal glue or vegetable oil which each boiled up according to their own closely guarded formula. Part of the success of Gutenberg’s printing innovation is due to the special ink he developed for transfer to and from the cast metal type. Ink making became a commercial process in the 17th century, and the first ink factory in America was established in 1742.

Little color was used in inks until the discovery of coal tar types in the middle of the 19th century though early Chinese printers had added some earth elements to their inks even before Gutenberg’s time. Linseed oil (a vegetable oil) was the main vehicle in printing ink until the mid-1930s when new vehicles (oils and resins containing specific chemicals depending upon what the inks are going to be used for) were introduced for letterpress printing in the United States. UV (ultraviolet) and EB (electron beam) curing vehicles for ink and coatings were introduced in the 1970s. More recent developments in inks have been water-based ink for gravure and flexography, and soybean ink for lithography.

In classical times the ink consisted of soot, gum arabic and water. Shady Characters has an interesting piece on the inks used in Roman manuscript work in which he tells of an early use of metallic inks found at Herculaneum, thus dating to 79CE. For those who crave the condition of a scribe here are instruction on how to make your own ink (remarkably simple, though not as simple perhaps as going out and buying a bottle of ink).

Today printing inks are made of four basic components: 1. pigments to color the ink and make it opaque; 2. resins, which bind the ink together into a film and make it stick to the printed surface; 3. solvents to make the ink flow; and 4. additives which alter the physical properties of the ink to make it suitable for different types of printing. It is a two-stage process: first they make the varnish, which is the base/vehicle used for all inks, though its recipe will vary depending on what the ink is to be used for. It is made by mixing the resins, solvents and additives. The resins react together to create some larger molecules which make the varnish more viscous the longer these reactions go on. In the second phase the pigments are mixed into the varnish, a process which can be seen in the rather lyrical video about modern ink making which can be found here. It’s well worth watching.

 

Advertisements