Printers

Dotty Printing - making images from coloured dots.

The old fashioned dot-matrix printers of twenty years ago worked by having a printhead which had a number of pins which were fired towards the paper with an inked ribbon coming between the pins and the paper. A character, whether letter or number, was printed when a set arrangement of pins fired in sequence and it was often possible to see how the individual dots made up the character as the pins were relatively large. Dot-matrix printers have largely been superseded now but the technology is still seen in some shops printing out till receipts.

Although dot-matrix printers are a thing of the past, the method of printing with dots is still very much with us and is the most cost-effective way for the individual to print out his pictures.

Laser and inkjet printers are in this category.

Colour laser printers, although not commonplace, have come down in price in the last few years to the point where individuals can afford them. Their use for photographic work is probably limited as the images produced often lack life. In an office situation a laser would probably be the printer of choice as they are fast and relatively inexpensive to run, especially for black and white printing.

Inkjet printers are the most common home printers today. They are capable of producing high quality prints at reasonable cost. As they are the normal choice of the photographer they will be discussed later at length.

Continuous Tone Printing - just like the wet ones

There are some printers which do not make their output from dots, these are called continuous tone printers. The most common type is the Dye Sublimation Printer which works by heating a ribbon which contains the dye to the point that it becomes gaseous. The gas then hits the print medium and returns to a solid state. Although the resulting prints are often superior to inkjet ones, it is expensive, slow and often quite tricky to do although it is possible to print on a wide range of surfaces. Largely the province of the professionals.

Inkjet Printers - in more detail

Inkjets have improved at a fantastic rate in the last decade in parallel with the development of the digital camera. Although still open to dispute, the best of the modern inkjets produce colour prints which are as good, if not better, than the wet prints they have largely replaced. What is indisputable is that the skill level necessary to produce an excellent inkjet print is so much lower than that required to produce the same quality wet print that colour printing is no longer the province of the expert; it is open to anybody prepared to put a modicum of effort into learning how to do it well.

The old dot-matrix printers had, commonly, about 24 pins in a print head which was about 1/4th of an inch across. This corresponds to a printing resolution of roughly 100 dots per inch, insufficient to produce an acceptable printed image. Today's inkjets are advertised as being capable of resolutions of many thousands of dots per inch; so many, in truth, that it has ceased to be a useful measure of a printer's quality - they can almost all produce so many very small dots that resolution is no longer a deciding factor when purchasing a printer.

(Although largely irrelevant it is interesting to note that some printers are capable of dispensing ink in volumes approaching one picolitre (10^-12 litres). To put that a more understandable way, if we compare a litre to the distance from the earth to the sun then a picolitre compares roughly to the span of your hand).

Although inkjet printing is dotty, the best modern prints will only appear so under magnification. This is because the ink is allowed to spread a little when it hits the paper thus filling in any gaps between dots. Large amounts of time and money developing have been spent developing inks and papers such that it is the ink/paper combination which decides the final quality of the print. The printer is just the means of getting ink onto paper and choice of printer is more about that than anything else today.

Choosing a printer

What size is your largest print going to be?
Most inkjets are capable of printing up to a maximum of A4 (210mm x 297mm), is this big enough or do you want to print A3 or even larger? The larger the print size the higher the cost of printer, paper and ink; if you go over A3+ (329mm x 483mm) the the price gets very high indeed.

How much can you spend?
It is possible to buy a colour inkjet printer for under £30 today. It is equally possible to pay over £300 for a high quality A4 model. You get the same size print from both but you get what you pay for in terms of both quality of printing and quality of printer. Most of the highest quality printers are a bit larger, expect to pay £350 to £550 for the best A3+ printers.

How much will the printer cost to run?
Don't forget to factor in the cost of ink and paper. The consumables cost varies not only with printer manufacturer but also, and more so, whether you stick with the 'official' inks and papers or use third-party ones. The cost savings can be enormous but the quality of the results can be appalling.

How good are the prints?
Unless you are lucky enough to be able to convince someone to print out the same image on a whole range of printers it is going to be very difficult to tell directly. The only way many of us to get any idea is either by personal recommendation or by reading the reviews.

Remember that you are buying a means of getting ink onto paper and the best results are not likely to be from using Fred Bloggs Cheapo inks on Acme paper.

Inks and Papers

As inkjet printers are developed they seem to be growing ever greater numbers of colours of ink. It is common to find light versions of the darker cyan and magenta inks and modern printers can have three different levels of grey or black ink. When they first arrived, they normally had four CMYK inks but it quickly became apparent that the four were unable to reproduce either bright colours or good dark ones, particularly good blacks. The problem of using the CMYK subtractive process to emulate the RGB additive system is that adding inks makes for a darker, muddier, result where adding additive colours, as one does on-screen, makes for more brightness. Including a lighter ink enables a lighter result to be achieved when inks are used together, an obvious advantage.

Manufacturer's Original Inks or third party inks.

It is true that the printer manufacturers make a lot of their profits from selling ink and paper as they recoup the majority of a printer's R and D costs from them. These are costs the independent ink producers do not have so they are able to sell ink more cheaply. Testing does show that many third party inks and papers do not match up to the printer manufacturer's offerings so going for the cheap option should be considered with caution. If one does a lot of printing it is worth considering using one of the Continuous ink Systems (CIS) which feed ink into the printer from bottles which sit outside the printer. Good quality CIS systems do have a good reputation for quality.

The printer manufacturers would have one believe that the choice of paper is as critical as that of ink. Whilst many of their papers are top-notch, many independent ones are too so some experimentation may be called for. It is important to remember the relationship between any one printer, ink and paper is unique. If you change any item in that list a new print profile will likely be required to control its use. As getting good printer profiles can be both expensive and time-consuming, it is sensible to limit oneself to using one inkset and a limited number of papers with a printer once one is happy with its output.

Colour Management Issues

The intricacies of ICC colour management are dealt with in much more detail elsewhere, both on this site and on the internet and in books generally.