Definition of laser printing
Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics (and moderate-quality photographs) by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially charged image.1 The drum then selectively collects electrically charged powdered ink (toner), and transfers the image to paper, which is then heated in order to permanently fuse the text, imagery, or both. As with digital photocopiers, laser printers employ a xerographic printing process. However, laser printing differs from analog photocopiers in that the image is produced by the direct scanning of the medium across the printer's photoreceptor. This enables laser printing to copy images more quickly than most photocopiers.
Źródło: https://en.wikipedia.org/wiki/Laser_printing
About printing companies
Paints, inks, paper, toners, foils and other consumables - these are things that can not be missing from printing plants. They are ordered wholesale and also consumed in bulk. For each order, the production costs are optimized, and the appropriate technique and type of printing is selected.
Graphic designers, DTP operators and printers deal with this. They are responsible for the quality of the printout and as soon as something is wrong they are the first to be targeted by the dissatisfied boss. Their work is quite hard and I have to admit that you have to really have a fuss to do it. Work after hours, maximum focus and responsibility - definitely not work for everyone.
Toner cartridges assembly
Regeneration of printer toner allows you to use them for a longer period of time. Thanks to this, you do not have to pay additional costs to replace them. It should be admitted that people who use toners installed in large printers for the first time may have problems with placing them in the printer in such a way that a large number of good quality prints can be made. That is why there is no shortage of such professionals who work on printer toners. They have the appropriate knowledge and tools that allow them not only to replace the toners, but also to repair the entire printing device, if such an order will receive from the incoming customer. Thanks to this, they can fully develop their business.