Printing your photographs in the comfort of your home or studio is one of the coolest things you can do as a photographer. It's also growing in popularity, and one of the key reasons for that is quality, affordable technology.
Talking about printers, let's have a look at the most widely used technology: inkjet printing.
Inkjet printers range from small printers destined for family and general home use, to large, professional models that cost thousands of dollars. When they first came out in the 1980s, their cost was pretty high. Over the years though, technology has gotten a lot better with prices dropping significantly.
But how do they work? Keeping it simple, an inkjet printer sprays extremely small ink droplets on paper to create an image. These tiny drops are about 60 microns in diameter, whereas a human hair is 70. The positioning of these dots is very precise and resolutions can go up to 2880x1440dpi or more. All those small drops have different colors, and combining those results in color photographs.
If we break it down to individual components, inkjet printers have a print head that does most of the work. It has a few nozzles that spray the ink onto the paper. The ink is stored in replaceable ink cartridges that come in various combinations, depending on the manufacturer. Some models use ink cartridges that incorporate the printing head. A print head stepper motor and a belt move the print head over the surface of the photo paper and for precision of movement a stabilizer bar is used.
Most inkjet printers have a tray for loading the paper and a set of rollers pulls the paper inside for printing.
Currently there are two ways for printers to form their droplets. One of them is the thermal bubble. Ink forms bubbles after tiny resistors create heat. After this bubble expands, part of it is pushed out of the nozzles and onto the paper. When it pops, it creates a vacuum that pulls more ink from the ink head. Bubble jet print heads have between 300 and 600 nozzles, all of them capable of firing a drop at the same time. Canon and Hewlett Packard are two of the manufacturers who use this technology
The other ink jet printing process is called piezoelectric and it's an Epson patent. Behind the ink reservoir of each nozzle, there is a piezo crystal that vibrates when it recieves an electrical charge. When this vibration is inward, a tiny amount of ink is forced out of the nozzle.
When the crystal vibrates out, it replaces the sprayed ink by pulling more of it from the reservoir.
Both of these are advanced, highly capable technologies that can satisfy the pretentious photographer. If you're not entirely convinced about investing a considerable amount of money in home printing, there are plenty of affordable options that can at least give you quality in smaller formats.