Books, books, books….they’re everywhere! So, just how do you get your news…from the local newspaper or on the internet? With the development of the internet, we’re seeing much more content online, but I don’t think the printed word will disappear any time soon. Nothing quite like a soft couch and a good book in your hands.
The printing press was invented in Germany in 1447 by Johannes Gutenberg, and has been thought by many as the most influential device ever. Germany has been a leader in printing and is still known for their printing machinery. Heidelberg, both a city and a company, manufactures several multi-million dollar printing presses.
I worked for a publishing company for about 10 years, and got to know the ins and outs of the production side of publishing. I had the opportunity to run address labelers, book binders, and printing presses….very interesting job.
One of the more common forms of printing today is offset printing. Here’s how it works:
An image is burnt onto a photo-sensitive aluminum plate, other materials can also used, and then attached to a plate cylinder. As the press runs, water is first applied to the plate cylinder and sticks to the non-printable areas.
Next the ink is applied…and since water and oil (ink) don’t mix, the ink only goes where there is no water–the printable areas.
As the plate continues to rotate, it comes in contact with the offset cylinder and transfers the ink as a reversed image onto it. Then the offset cylinder continues on around until it comes in contact with the paper…the image is reversed again as it is transfered onto the paper.
The paper continues on, and is folded and cut into pieces that can be made into magazines, books, etc…
That is the process for printing one color onto a sheet or continuous web of paper…in the case of newspaper, this would most often be black. It is however a bit more complicated to print a color image like a photo or drawing. First a little about color.
So what are the primary colors…well that depends on the medium. The three primary colors of light are red, green, and blue (RGB). They are considered additive primaries–when you add a color, it adds to the final color. You can see illustrations of this on the internet…just right click on most any website, and then click “view source”. Most of what you see will look like gibberish, but occasionally you’ll see numbers like (#FFFFFF, #34F4C2, #111111, etc…).
I’m not going to go too in depth, but these are called HEX numbers. The first two digits represent the red level, the second two the green, and the third two the blue. So with our example (#34F4C2) red=32, green=F4, and blue=C2. If you want to see how hex numbers work, check out the online Color Schemer, and play around a bit. By the way….#34F4C2 is a light-blue color. I use this website often to see which colors work well together.
The three primary colors of ink or pigment are cyan, magenta, and yellow, and they are considered subtractive primaries–when you add colors, it subtracts or absorbs the wavelengths of light you don’t see, and reflects the wavelengths of light you do see. Check out the color chart.
SO….when printing a color image, the sheet or web of paper must pass through four different colors….(cyan, magenta, yellow, and black). Black is added because it’s hard to make a true black by mixing the other three color pigments.