LASER · TONER
Drawn with light
A laser writes the page as an electrical image on a drum, which picks up powdered toner that heat then fuses to the paper.
Where it beganThe box on the desk is cleverer than it looks.
One kind draws your page with a laser and fuses powder onto it. The other fires tiny drops of liquid ink. Here is how both work, why A4 is the shape it is, and what the numbers on the box mean.
Plain English, with the sources linked.
- Laser draws, toner sticks
- Inkjet sprays drops
- A4 is half of A3
- Print on both sides
LASER OR INKJET
Two ways to put marks on paper.
Both are non-impact printers:
nothing strikes the page, unlike the old typewriter-style machines.
INKJET · INK
Sprayed in drops
An inkjet head fires tiny drops of liquid ink straight onto the sheet. Thermal inkjet reached desktops in 1984.
Cartridges and yield
PAPER · ISO 216
The sheet itself
A-series paper keeps the same shape when you halve it, which is why A4 scales cleanly to A3 or A5.
Try the size explorer
PRINT SMARTER
Four habits for
a calmer printer.
Turn on two-sided printing
Energy-efficiency guidance recommends making sure duplex mode is enabled, so one sheet carries two pages.
Let it sleep
Set the printer to drop into low-power sleep when idle, and switch off equipment you are not using rather than leaving it on standby.
Compare yields, not just prices
Colour inkjet cartridge yields are measured under ISO/IEC 24711 with standard test pages on plain paper. Dividing price by yield gives a fairer comparison than price alone.
Give a laser printer some air
If you print a lot on a laser printer, keep the room well ventilated, as the 2007 particle researchers suggested.
TWO NUMBERS WORTH KNOWING
Fast from the start,
not quite clean.
Laser printing arrived quickly,
and later research measured what some put in the air.
60 pages a minute
Prototype built from an office copier
Working at Xerox PARC, a physicist modified a standard copier into the first laser printer within about a year. The prototype printed 60 pages a minute at 500 dots per inch.
THE FIRST LASER PRINTER · 1971
17 of 62
Laser printers tested in Brisbane
Researchers at Queensland University of Technology classed 17 of 62 laser printers as high emitters of ultrafine particles. Emissions were higher with new toner cartridges and when printing graphics and images.
PARTICLES IN THE AIR · 2007
Emissions varied with printer model, age and cartridge. The researchers' practical advice until regulation caught up was simple: keep rooms with printers well ventilated.
PAPER SIZE EXPLORER
How big is
that sheet?
Pick a paper size to see its dimensions and how its area compares with A4. A-series sizes come from the international standard ISO 216, which defines A0 as one square metre.
Each A size is exactly half of the one above it, cut across the long side, and every one has sides in the ratio of the square root of two.
PRINTER FACTS
Five things worth
printing out.
A ratio from 1786
The idea of a sheet whose halves keep its shape goes back to a letter by Georg Christoph Lichtenberg in 1786. It became the German standard DIN 476 in 1922 and the international ISO 216 in 1975.
Sixteen A4 sheets make a square metre
A0 has an area of one square metre. Halve it four times and you reach A4, at 210 by 297 mm.
Laser printing is older than the PC
Xerox researchers demonstrated laser printing in 1971, made it a networked office printer in 1974 and proved it commercially with the Xerox 9700 in 1977.
Inkjet came to the desk in 1984
The first desktop printer to use thermal inkjet technology was introduced in 1984, bringing ink-drop printing to the office desk.
Efficient models use up to 35% less energy
ENERGY STAR certified imaging equipment, such as printers, copiers and scanners, uses up to 35% less energy on average than standard models.
QUICK QUESTIONS
Printers, answered.
Short answers to the questions people ask most.
What is the difference between a laser and an inkjet printer?
A laser printer uses a laser to draw the page as an electrical image on a drum, which picks up powdered toner that is fused onto the paper. An inkjet printer fires tiny drops of liquid ink straight onto the page.
When were laser and inkjet printers invented?
Xerox researchers demonstrated laser printing in 1971 on a modified office copier, and the Xerox 9700 proved it commercially in 1977. Thermal inkjet reached desktops in 1984.
Why is A4 paper 210 by 297 mm?
A-series sheets have sides in the ratio of the square root of two, so cutting one in half gives two sheets of the same shape. A0 has an area of one square metre, and A4 is A0 halved four times.
What does page yield on an ink cartridge mean?
For colour inkjet cartridges, yield is measured under ISO/IEC 24711 by printing a defined suite of test pages on plain paper. It lets you compare cartridges fairly, but your own pages may use more or less ink.
Do laser printers give off particles?
A 2007 Queensland University of Technology study of 62 laser printers classed 17 as high particle emitters, with more emitted from new toner cartridges and when printing images. The researchers advised good ventilation.
Sources
Each figure on this page comes from the sources below.
- Laser printers: from a modified copier to the officeComputer History Museum
- Development of the commercial laser printer, 1971-1977IEEE Milestone (ETHW)
- The first desktop thermal inkjet printer (1984)Centre for Computing History
- International standard paper sizes (ISO 216)University of Cambridge
- Laser printer particle emissions study (2007)Queensland University of Technology
- ENERGY STAR imaging equipmentNatural Resources Canada