Contents: What Is an Offset Lithograph?
What Is the Meaning of Offset Lithograph?
First, the whole foundation of lithographic printing is based on the fact that water and oil just don’t mix together.
Now, for the fun part…
I suggest you watch the video below to get a beginner’s take on what offset lithographic printing is all about.
Now, for a more detailed look at how offset lithographs are made and what an offset lithograph looks like, check out the video below.
The term litho printing can be used interchangeably with offset lithographic printing. Both terms mean the same thing.
So, in a nutshell…
Offset lithography printing begins with the pre-press stage where a digital file is broken down by color (usually 4 colors: cyan, magenta, yellow, black).
Then, a laser etches these 4 different colored images to 4 different undercoated aluminum plates called printing plates (or sometimes called press plates).
Each of these 4 printing plates is then loaded onto 4 rollers known as the plate cylinders.
During the printing process, the plate cylinders start to continuously roll. Meanwhile, each plate cylinder is being dampened with water and oil-based ink.
Now, why would you want the printing plate to be dampened with water and oil? Because the oil-based inks stick to the image area but do not stick to the negative areas (the areas where there’s no image).
Now, the image on the plate cylinder is image is printed on another cylinder with a rubber blanket, called the blanket cylinder. The addition of this “blanket” process results in a clearer and sharper final image and is where offset printing gets its name.
Paper is loaded, one by one, into the start of the press and is passed between the 4 different colored blanket cylinders and yet another cylinder, called the impression cylinder. When the paper is between the blanket cylinder and the impression cylinder, it receives the printed image in one of the CMYK colors and is then passed on to the next blanket/impression cylinders to receive another color.
After the page has traveled through each of the 4 different colored units, it is piled at the end of the press with a thin layer of powder separating each page so that the printed image can dry without sticking and marking the other pages above and below it.
Offset printing is best suited for larger volume prints as most of the cost is in the initial setup and the price per print will fall as the quantity goes up.
What Is the Difference Between a Lithograph and an Offset Lithograph?
What Is the Difference Between Offset Lithograph and Poster?
Are Offset Lithographs Valuable?
An offset lithograph print is usually much less valuable than original art created by a well-known artist or a hand-printed lithograph, but offset lithographs can still have the potential of being valuable.
Some factors that have the potential to increase the value of an offset lithograph are as follows:
- Has a limited quantity (limited edition)
- Is numbered (another sign that it’s from a limited edition)
- Is signed by the artist