PrintersPrinters

a users’ perspectivea users’ perspective

There are two major typesThere are two major types

LaserLaser Inkjet (or bubble-jet)Inkjet (or bubble-jet)

TechnobabbleTechnobabbleLaser Printers are peripherals that use a series of mirrors and lenses to "apply" the text or image onto an internal revolving drum.

This application is accomplished by changing the electrical polarity of the drum's surface in the appropriate places.

Toner, which is electrically charged with the opposite polarity of the image on the drum, is then applied to the drum and adheres in the designated pattern.

Paper heated to a precise temperature is then sent past the drum, which applies the toner to the page.

LasersLasers

From the user’s point of view, the result is generally a 600 dots per inch image

It is cheap and consequently ideal for high It is cheap and consequently ideal for high volume environments.volume environments.

The initial outlay is high but cost per page is The initial outlay is high but cost per page is around 2 cents as opposed to 23 cents for around 2 cents as opposed to 23 cents for inkjets.inkjets.

The break-even point for black and white is The break-even point for black and white is around ten pages per week.around ten pages per week.

LasersLasers

Colour lasers require four sets of everything Colour lasers require four sets of everything – drums, rollers and toner.– drums, rollers and toner.

Most lasers for the cheaper (home use) can Most lasers for the cheaper (home use) can only be refilled up to (usually) about four only be refilled up to (usually) about four times.times.

Replacement rollers, drums, etc can cost Replacement rollers, drums, etc can cost around $250, making $1,000 total, thus around $250, making $1,000 total, thus making a new printer a viable option.making a new printer a viable option.

LasersLasers

Colour laser printers are not generally Colour laser printers are not generally considered viable for the home user considered viable for the home user because:because:

The colour tends to be ‘bright’ like an The colour tends to be ‘bright’ like an advertisementadvertisement

The long-term cost makes ink-jets more The long-term cost makes ink-jets more viable.viable.

They cannot print on ‘coated’ papers.They cannot print on ‘coated’ papers.

LasersLasers

The hot paper requirement of lasers has The hot paper requirement of lasers has been utilised in an interesting way:been utilised in an interesting way:

Coloured plastic sheets can be placed on a Coloured plastic sheets can be placed on a previously printed page and fed back previously printed page and fed back through the printer.through the printer.

The black text picks up more heat that the The black text picks up more heat that the white paper. The plastic melts on to the white paper. The plastic melts on to the black text but not the paper, giving black text but not the paper, giving interesting patterns (metallic gold, etc).interesting patterns (metallic gold, etc).

Ink PrintersInk Printers

Ink-jet printersInk-jet printers. When a quartz crystal is . When a quartz crystal is squeezed, it produces an electrical current. squeezed, it produces an electrical current. When a currant is applied, it distorts. This When a currant is applied, it distorts. This characteristic is used to force the ink out.characteristic is used to force the ink out.

Bubble-jet printersBubble-jet printers. The ink is heated to a . The ink is heated to a vapour and thus forced out of the nozzle.vapour and thus forced out of the nozzle.

From the USER’S point of view there is From the USER’S point of view there is therefore no difference.therefore no difference.

TechnobabbleTechnobabble

In bubblejets, the ink is heated to over In bubblejets, the ink is heated to over 600600ooC.C.

It leaves the print-head at about 500 inches It leaves the print-head at about 500 inches per second.per second.

No wonder it splashes if it hits the wrong No wonder it splashes if it hits the wrong surface.surface.

Ink PrintersInk PrintersThe Resolution of your printer depends on:The Resolution of your printer depends on: The number and spacing of holes in the print The number and spacing of holes in the print

head (around 1,120)head (around 1,120) The size of the holesThe size of the holes The speed of the paper past the headThe speed of the paper past the head The type of ink usedThe type of ink used The type of paperThe type of paper Photocopy papers absorb the ink, ‘wick’ it; Photocopy papers absorb the ink, ‘wick’ it;

‘feather’ it or let it flow into microscopic ‘feather’ it or let it flow into microscopic crevasses.crevasses.

Types of printer inkTypes of printer inkWater-based – Until recently this was the Water-based – Until recently this was the

most usual but the ink tends to feather or most usual but the ink tends to feather or bleed and is unsuitable for the high bleed and is unsuitable for the high resolutions required in today’s market.resolutions required in today’s market.

Types of printer inkTypes of printer inkOil based – The droplets can be formed Oil based – The droplets can be formed

using very small quantities of ink, so it is using very small quantities of ink, so it is suitable for high resolution printers. suitable for high resolution printers.

Expensive. Expensive.

Can clog, especially if the printer is not used Can clog, especially if the printer is not used for a few days.for a few days.

Types of printer inkTypes of printer inkP-POP. A coagulant is incorporated in with P-POP. A coagulant is incorporated in with

the black reservoir. This is sprayed on to the black reservoir. This is sprayed on to the paper before the ink, so coated papers the paper before the ink, so coated papers are not required. The idea does not are not required. The idea does not appear to have caught on and is being appear to have caught on and is being phased out.phased out.

Types of printer inkTypes of printer inkPhase-change inks. These are solid at room Phase-change inks. These are solid at room

temperature and heated before ejectiontemperature and heated before ejection

No feathering. However, these are No feathering. However, these are unsuitable for home use since they need unsuitable for home use since they need to be run at high volume.to be run at high volume.

Print itPrint it

For best quality, print at twice the graphic For best quality, print at twice the graphic resolution onlyresolution only

Use coated paper – gloss, semi matt or matt Use coated paper – gloss, semi matt or matt – this prevents bleeding– this prevents bleeding

There is no white ink, so use the whitest and There is no white ink, so use the whitest and brightest paper you can get.brightest paper you can get.

Quality counts – use the best inks, the best Quality counts – use the best inks, the best paper and the best printer you can afford.paper and the best printer you can afford.

Micrograph of ink at 1440 on copier paperMicrograph of ink at 1440 on copier paper

on 1440 matt paperon 1440 matt paper

on 1440 glossyon 1440 glossy

on HP2000 matt photo paperon HP2000 matt photo paper

Special PapersSpecial Papers

There are a wide variety of There are a wide variety of specialtyspecialty papers papers available –available –

Pre-printed for labels, certificates, parties, Pre-printed for labels, certificates, parties, formal occasions, etc.formal occasions, etc.

ColouredColoured, , stippledstippled and pre-cut giving the and pre-cut giving the effect of parchment, papyrus, hand-made, effect of parchment, papyrus, hand-made, cloth, etc.cloth, etc.

One allows the high-speed ink to permeate One allows the high-speed ink to permeate the gloss surface, giving it a water-proof the gloss surface, giving it a water-proof finish.finish.

Colour GamutColour Gamut

Buying a PrinterBuying a Printer

Print-head built in: this is the ideal type Print-head built in: this is the ideal type because the holes can be machined to a because the holes can be machined to a greater accuracy. However, if the printer is greater accuracy. However, if the printer is left for more than a week it can clog and it left for more than a week it can clog and it takes an expert to clean.takes an expert to clean.

Buying a PrinterBuying a Printer

Print-head part of the ink reservoir. These Print-head part of the ink reservoir. These are mass produced and can vary slightly. are mass produced and can vary slightly. However, if the head clogs, it is a simple However, if the head clogs, it is a simple matter to clean or replace the cartridge.matter to clean or replace the cartridge.

Buying a PrinterBuying a Printer

Reproduction. The colour will vary between Reproduction. The colour will vary between manufacturers and between machines.manufacturers and between machines.

The more colours used, the better the output The more colours used, the better the output (usually).(usually).

Buying a PrinterBuying a Printer

Always take a disk with a photograph on it in Always take a disk with a photograph on it in to the shop and ask them to print it for you. to the shop and ask them to print it for you. Compare it with a print you like.Compare it with a print you like.

Look for skin tones and reproduction of fine Look for skin tones and reproduction of fine lines (hair, etc).lines (hair, etc).

Look for artifacts – spots and marks that are Look for artifacts – spots and marks that are not on the original.not on the original.

Buying a PrinterBuying a Printer

Resolution.Resolution. Generally, the higher the Generally, the higher the resolution, the slower the print and the more resolution, the slower the print and the more expensive the machine and the cartridges.expensive the machine and the cartridges.

As the resoloution increases, the number of As the resoloution increases, the number of holes increases and their size decreases.holes increases and their size decreases.

This increases the chance of ink blockage.This increases the chance of ink blockage.

Buying a PrinterBuying a Printer

An ink printer should be An ink printer should be usedused every day or every day or the ink may dry on the head causing the ink may dry on the head causing blockage.blockage.

Some printers incorporate the print-head Some printers incorporate the print-head with the reservoir, thereby increasing the with the reservoir, thereby increasing the cost. However, for home use this is ideal cost. However, for home use this is ideal because if the ink dries or blocks, it is a because if the ink dries or blocks, it is a simple matter to replace the cartridge.simple matter to replace the cartridge.

Buying a PrinterBuying a Printer

Others incorporate it with the printer itself.Others incorporate it with the printer itself. This saves on replacement cartridge costs This saves on replacement cartridge costs

and gives a more accurate print head. and gives a more accurate print head. However, cleaning a blocked head becomes However, cleaning a blocked head becomes time consuming and expensive.time consuming and expensive.

Ideally, this type of printer should be used Ideally, this type of printer should be used every day and never left idle over holidays, every day and never left idle over holidays, etc.etc.