In this installment of the history of signs and graphics printing, I’ll talk about the vast improvements in signs and graphics printing from the mid-1800′s until late in the 20th century. And where the two trades of signs and graphics printing intersected to create a significant change for many sign makers.
To recap the previous three articles on the history of signs and graphics printing, we’ve talked about how signs came to be used in the West and the wood sign gave way (mostly) to electrical and neon signs in the past 100 years or so. Signs and graphics printing by sign makers has never been so fascinating – much of this information is new to me, so I hope it is for you as well!
While this is part 4 of this series, it is really the second part of the history of signs and graphics printing and how eventually sign makers came to integrate printing into signs and graphics prints.
The last major improvement in signs and graphics printing we talked about in the last article was roll printing, in which large rolls of media could be printed at high speeds. This improvement in the signs and graphics printing process took place about 1863.
Lithography In Signs And Graphics Printing
I’m going to backtrack slightly to 1796. A signs and graphics printing process called Lithography was developed by an innovative Bavarian author by the name of Aloys Senefelder. The reason I am backtracking to this method is because it became one of the signs and graphics printing methods used in by sign makers later, or at least in part.
In Lithography, chemicals are used to create an image. Without going into the gory details (which are really above my head and I’m just not into chemistry – I just like what it can do!), we’ll just say there’s some positive and negative images, that combined, produces very nice signs and graphics. Today, most books are printed using offset lithography, or offset printing for short. Posters (large runs), maps, packaging, and newspapers are also produced with this method, as well as some types of signs.
Major improvements in Lithography came later into the 19th century with the addition of color (chromolithography). This process is reputed to be the antecedent to 4-color process printing which is the basis for most color signs and graphics printing today.
Another improvement to lithographic printing was the addition of offset printing, in which the inked plate was transferred to a rubber blanket, and then to the printing substrate such as metal or paper or plastic. Again, there’s some chemicals and water used in this process that I won’t go into, but this improvement is still used to this day in signs and graphics printing, books, packaging, and many other high speed print items.
Flexographic Signs and Graphics Printing
Another signs and graphics printing innovation is known today as Flexographic printing. Initially, in 1890, when the first rubber printing plates were used with water-based inks, the results were fast but smeared too easily. New aniline inks were developed within 15 to 20 years that worked great for signs and graphics, particularly with food packaging. The process was called “aniline printing” at that time, but the inks were classified in the 1940′s by the FDA as unsafe for food packaging, and although new, safer inks were developed in 1949, the food industry shied away from aniline signs and graphics printing, so in 1951, Frank Moss renamed aniline printing to flexographic printing, and this signs and graphics printing category was reborn.
In the 1990′s, rubber plates were replaced with photopolymer plates, and the signs and graphics print quality improved dramatically with this innovation. The photopolymer plates are also easier to create now, and digital “direct-to-plate” technology has been developed which has also made the signs and graphics printing process much faster as well. Finally, with these improvements, lithography now rivals offset printing quality.
There’s more knowledge to grasp when it comes to printing methodology. Find out for more in here: www.visigraph.com
You may be interested in: