On the face of it, laser and inkjet printer technology provide the same result, a colourful image on a piece of paper. Those of you that have used both, will no doubt be aware that there are marked differences in quality as well as the range of substrates that are available for each technology. We are often asked why, so here are years of knowledge in a few paragraphs.
The main difference between the two is the type of medium used to generate colours. Laser uses powder and inkjet uses ink. This has implication of both colour density and accuracy, as well as the type of media and the coatings required to absorb and hold the colour on the paper.
Laser printers use a CMYK range polymer based powder which is laid on an electrostatic drum before it is transferred to the paper. At the point of transfer from the drum to the paper, the powder is laid loose on the paper and must go through a hot fusing process in order to become permanent. Paper for these printers needs to be compatible with static electricity and more importantly, be stable when heated.
Laser imaging technology also is limited to a resolution of about 720dpi and does not handle sub tones very well, making skin tones and solid colours inaccurate and often blotchy. Although this resolution was on par with inkjet technology about 8 years ago, these days it does not come close to the maximum resolution available in the inkjet process. Images printed with laser therefore are lower resolution and are normally used for presentations and higher run documents rather than the top quality photographic quality.
Everybody knows that laser printers using laser photo paper producing full colour work and immensely faster than inkjet. Another consideration when deciding which technology to adopt.
Inkjet printers on the other hand are all about quality of image and range of papers and films that can be put through them. Modern inkjet printers can use up to 9 different colour cartridges at the same time to achieve amazingly accurate photographic images. Although most people would use a standard 4 colour inkjet printer (same CMYK as laser but in liquid ink form), the jet (as in Ink-Jet) technology is much finer and more accurate than laser. Inkjet printers can produce results almost on par with wet process photographic development of years gone past.
Inkjet printers achieve a high colour accuracy and wide tonal capability by spraying a highly accurate, almost microscopic jet of ink (measured in pico-litre if you want to get technical) onto the paper. When laser printers try to do the same, they spread layers of coloured toner (similarly to dust) on the paper, thus mixing the colours in layers to try to achieve the image. The result is less defined, lower in resolution and does not handle solid colours as well.
With inkjet compatible papers, the absorption of the colour is done exclusively by the coating technology of the paper. Inkjet coated papers have a chemical coating that is designed to receive the wet jets of ink and stop them from spreading as they hit the paper. Good inkjet papers do it without distorting the paper itself (remember that you are essentially spraying paper with liquid) while maintaining the sharp image quality and maintaining the wide colour gamut and tonal range that the printer is capable of.
Remember the hot fusing process in the laser technology that fuses the toner powder onto the paper? Well, it is totally missing from the inkjet technology, thus lending itself to a much wider range of products that can be fed through the machine. Inkjet printing media includes high gloss photo papers, vinyls and self adhesive papers as well as super heavy products up to 350gsm which can not normally be used on laser printers. They also have a simpler paper path (no drums and paper turning around in a printer before being extracted, which means stiffer products can be used.
The decision between the two technology revolves around speed of printing required, image quality required and the cost of running the machine. Laser printers can be cheaper to run but are more expensive to buy. If high photographic image is needed then photographic inkjet photo paper is the only option and if you need to print on specialised surfaces, then the decision becomes clearer.
Interestingly, most offices that run laser printers will also have one or two inkjet ones also. The low cost of inkjet printers that can product amazingly high image quality, make the two technologies complimentary. And if all you do is write letters and print in black ink only, well this is an all together different article.