I’ll try to condense this article as much as possible because this is really a wide subject. Going too in depth could take forever and wouldn’t really be all that interesting for most. But 3 or 4 technological advancements are to blame for illustrations rapid evolution in the digital medium.
An art form
For the longest time illustration was not considered a real art form. That changed a lot just before the turn of the 20th century with the advent of offset printing presses and other technological advancements that gave artists more room to experiment since full color print of illustration was now possible.
Before that illustrators had to make a sketch and send it to a craftsman to make an engraving or woodcut to print with. The craftsmen were not really artists rather domestic workers and it’s needles to say that the prints usually didn’t really look like the original sketches.
With the advent of offset printing presses illustration got a huge boost with commercial publication as well as with books and propaganda prints. The offset printing press basically photographs the illustration through a glass with cross hatches that divide the illustration in to a series of dots that are either close together or far apart (that depends on the color tone).
Color printing is possible with the use of 4 colors. Those are cyan, magenta, yellow and key (black) or CMYK for short. A special halftone filter separates the colors. A purple filter isolates yellow colors, a green filter isolates magenta colors and a red filter to isolate the cyan colors. The black color is isolated using a combination filter. Each color is offset on to a rubber cylinder called a blanket and then printed of the cylinder on to a surface.
Computers shake the illustrating world
The next big breakthrough came with the advent of computer technology that consequently enabled the evolution of digital illustration. First computers were huge beasts that needed huge rooms to facilitate them but with the invention of monitors and other output devices artist got a new visual medium to experiment with.
In 1958 the TX-2 was invented at MITs Lincoln Laboratory. This specific computer pioneered a lot of computer interaction methods but it was specifically a breakthrough in computer graphics. In 1963 Ivan Sutherland presented the Sketchpad software that ran on a TX-2. The software used a special light pen that interacted with the TX-2′ CRT monitor. It enabled technical and artistic drawings directly on screen. This was invented even before the computer mouse. In a time when computer interaction was possible only by writing long code strings with a keyboard, this meant a revolution. It’s technically the forerunner to the graphic tablets used today.
The next revolution for artists came with the invention of the graphics tablet. Tablets enable manual illustrating like with a pen or pencil. The image does generally not appear on the tablet itself. Expensive high end, super sensitive touch screens do exist. Wacom may be pricey compared to other tablet manufacturers but they have the distinct advantage. Tablets are their only products and they REALLY know what they are doing. They also hold the patent for a wireless stylus that does not use batteries. Therefore they are not heavy on the hand and comfortable to use.
EDIT 23. 4. 2018: As of late a lot of other tablet manufacturers have entered the market that are giving Wacom a run for thier money. I don’t own any so I can’t comment on them.
The computer didn’t introduce just a new production method but also the option to distribute your work lighting fast. See my pros and cons of digital illustration to read more on that subject.
Illustration has come a long way in the last 100 years. Technology pushed it more in the 20th century then ever before. At first the digital medium was home to self taught artists because no one really had experience. Even though new ways of using technology to illustrations advantage are discovered every day, it’s clear that the digital medium has already made it’s place in history and is definitely here to stay.