6 Colour System
For good-quality photos you'll want a 6-colour photo printer which adds light cyan and light magenta inks to the 4-colour system, giving better gradations and skin tones. Do note that modern inkjets typically use pigmented black inks and hence sometimes you'll find 5-colour or 7-colour units that add a photo black (dye-based) ink to the mix.
8 Colour System
Various manufacturers have come out with their own 8-ink variants to produce even better quality prints. However, do note that at present none of these use the same colour inks. For instance, HP's Photosmart 7960 has been optimised for black-and-white prints--which also subtly improve colour outputs - with more shades of grey inks, while Canon's i9950 is tweaked to emulate positive film with the inclusion of red and green inks.
Borderless Printing
Also described as border-free printing at times, the term is used to define photo outputs with no borders, resulting in edge-to-edge printing.
Memory Card Slot
As most digital cameras use various types of memory card for storing photographs, a memory card slot is a useful feature for digital photographers. They allow you to take the memory card from your camera, plug it into the printer and print images directly from the card without using the computer. Memory card slots support the memory card formats popular in digital cameras, such as SD, MD and CompactFlash
CMYK
An acronym that stands for cyan, magenta, yellow and black. Almost all colour printers use the four basic colours of ink to produce a colour image, mixing them to get different shades and colours. This is generally called a 4-colour system.
Colour Management
A suite of software designed to increase the accuracy and consistency of colour between a scanner, display and printer.
Connectivity
The USB (Universal Serial Bus) is truly universal--all printers have either a USB 1.1 or the newer, faster USB 2.0 port. Don't worry too much if your system doesn't have USB 2.0--the two standards get along just fine, and USB 1.1 is fast enough for printing. Mac users can instead opt for FireWire (IEEE 1394) on some models. But if you want to go old school, you'll still find plenty of printers that accept those big, 25-pin parallel cables. Workgroup printers also support printing over a network using a standard Ethernet cable with an RJ-45 connector. For even better mobility, many models support printing wirelessly, using infrared, Bluetooth, and Wi-Fi access points with built-in print servers.
Cost Per Page
This is quite simply how much it costs to print out a page from the printer, or the cost of an ink cartridge divided by the number of pages you can print before the ink runs out. The type of printing you do will have an effect on the cost per page, as a page of black and white print will use less ink than a full colour photo.
Direct Connect Printing
This system bypasses the PC and comes in the form of a camera-direct or card-direct method. With the former, photos can be outputted simply by connecting a compatible digital camera and printer via a dedicated cable. For card-direct printing, see Memory card slot.
Dithering
Also known as halftoning, this is a process of varying size and pattern of dots of different color inks together to produce other colors. If the halftoning algorithms are good, gradations will be smooth and you won't see any visible dots. Better-quality photo printers generally produce little, if any, visible dither pattern in the light-colored areas where they are most noticeable. See also Halftoning.
Gasfastness
Durability of the prints when exposed to damaging pollutants in the air such as ozone. There are currently no standardized test for gasfastness. To combat this problem, manufacturers have produced swellable paper media which improves over porous paper media substantially. Read more from Photo printing: When paper ain't paper.
Halftoning
This process lies in the our eyes' inherent inability to distinguish spots that are closely spaced. To convert a continuous tone image to print--whether it is one-color printouts (grayscale) or multicolored (4, 6 or 8 inks)--various patterns of ink droplets are varied to produce more colors and scales. Read more in Dithering.
Inkjets
Inkjet printers function by spraying tiny dots of ink onto a page of paper. This process can produce black-and-white or color images, and in some cases, photo-quality images. However, inkjets can have trouble with sharp lines so text can vary from adequate to good depending on how fast the printer runs. Dedicated photo inkjets, on the other hand, are great for photos but generally not good for text.
Lightfastness
Durability of a print when exposed to light. When an ink is lightfast, it has strong light-fade resistance. Read more from Photo printing: When inks ain't inks.
Paper handling
The typical paper-handling specs on a printer include everything from the size and thickness of various paper to the standard and optional input- and output-tray capacity. It's enough to make your head spin. As a general rule, all inkjets and personal laser printers will print on standard paper (A4 size paper), accept envelopes, and have input and output trays that hold at least 100 sheets. The only exceptions are specialised printers such as snapshot and portable models. More advanced paper-handling features--such as A3 and larger size printing, duplexing (printing on both sides), and auto document feeders for faxing and copying--will be found on only higher-end models.
PictBridge
An open standard enabling the direct printing of photos from PictBridge-enabled cameras of any brand on any PictBridge-compatible printer.
Page Per Minute
Abbreviated as ppm. This specification is always exaggerated. Laser printers generally print text pages only slightly slower than the manufacturers' claims. But the claims for inkjets are typically done at low-quality settings while using very simple text pages - in other words, a speed you'll never see in real life. Reality check: Printing a single A4-sized colour photo on an inkjet may take anywhere from 2 to 30 minutes.
Print Cartridge
There are two variants of print cartridges in the market today. They can be referred to as separate ink and silicon technology and integrated cartridge technology. For the former, only ink exists in the containers. In the latter, the device integrates the printhead, ink cartridge and ink delivery system.
Printhead
The important, usually movable, part of a printer. This contains the printing elements directly responsible for applying ink to a medium. As a general rule of thumb, a printhead with more nozzles will have a larger print swath (coverage), resulting in faster outputs.
Print Quality
Generally, the lower the quality, the faster the print speed and less ink used. The higher the quality, the slower the print speed and better print results.
Print Sizes
The "Ax" size is a set of paper sizes established by the International Standards Organisation (ISO) that range from 2A0 (largest) to A7 (smallest). Size in millimetres: 1,189 x 1,682mm; Size in inches: approximately 46.8 x 66.2 inch.
Processor and Memory
Nearly all manufacturers provide information on the processor and the memory, but at least for personal use, these specs are relatively unimportant. Your computer does a fine job, largely on its own, of lining up print jobs and sending them on to be printed. If you have multiple users or you often print high-resolution photos or other large files, however, then you'll want a printer with a faster processor and more onboard memory.
Resolution
Usually measured in dots per inch or DPI. This indicates how many individual dots a printer can create on a page per square inch of area. DPI is typically listed as horizontal resolution by vertical resolution; the higher the dpi, the better the resolution.
Standard Photo Sizes
These are photo print sizes derived from 35mm film format (36 x 24mm) with an aspect ratio of 3:2 and large-format (4x5) film format. The standard ratio for 35mm negatives correspond directly to 4 x 6 inch (4R), 8 x 12 inch (S8R), 12 x 18 inch, 16 x 24 inch and 20 x 30 inch. It's also fairly close to 5 x 7 inch (5R) and 3.5 x 5 inch (3R). 3R (3.5 x 5 inch); 4R (4 x 6 inch); 5R (5 x 7 inch); 8R (8 x 10 inch) from 4x5 film negatives; S8R (8 x 12 inch); 11 x 14 inch close to 4x5 film negatives; 12 x 18 inch; 16 x 20 inch from 4x5 film negatives; 16 x 24 inch; 20 x 24 inch close to 4x5 film negatives; 20 x 30 inch.
