Despite advances in photo printing at home, monochrome printing is often a disappointment. 'Monochrome' refers to any picture in which a single tone is used, ranging from a shade that represents 100% of the colour to white; in this Intel I will be concerned with Black and White printing. Using an ink-jet printer equipped with the manufacturer's standard colour inks offers two alternative methods of printing in black-and-white. Including the coloured inks or limiting printing to the black ink.
Colour Inks - When you send a black and white image to the printer, the grey tones are produced by blending the cyan, magenta and yellow ink. This is how monochrome prints are handled by default, but it is not the ideal way to achieve either crisp blacks or neutral greys; instead, it often results in prints with colour casts - most often magenta predominates, but the cast may vary across the tonal range.
Pigment based inks are becoming more common, but most printers still use dyes. Because of the way these reflect light, their tones van vary with the type of illumination. An apparently satisfactory print can become quite unacceptable if it is moved from, say, daylight into artificial light. This variation of colour with illumination is called metamerism. In addition, coloured dyes can change as they age. Therefore, a monochrome print made with colour inks may also colour as it ages.
Black Ink - The human eye is very sensitive to colour variations; producing a convincing monochrome print with colour dyes is difficult. The obvious answer is to use just the black ink. This certainly results in a neutral-toned print; but monochrome is not just the black of the ink and the white of the paper. A true monochrome contains the full gamut of tones between. When printing with black ink alone, the intermediate shades of grey are produced by varying the distance between black dots, like newsprint print. The result is seldom acceptable.
Printer manufactures have recently started to address black and white issues seriously in their photo printers. Epson and Canon in particular, have made recent releases of dedicated black inks, promoting them as “Exhibition Quality” if they are used with the manufacturers' own paper stock. Specialist print supply houses can also supply inks designed for black and white output.
Monochrome Ink Sets – These ink sets replace the coloured inks in the printer with shades of grey. This eliminates the problem of colour casts, but where dyes are used, metamerism can still be a problem. Replacing dyes with pigments reduces or even eliminates metamerism, and because pigments are more stable than dyes the longevity of the print is also improved to the point where the top of the range inks now exceed the life of traditional photographic prints.
Another benefit of using a monochrome ink-set is that the palest tones in the image can be printed using only the lightest grey ink, the mid tones using the mid-grey ink and the darkest tones using dark grey and black ink. This results in a much smoother tonal gradation particularly noticeable in the highlights.
Whatever ink set you use, the printer has to be properly “set up”. Most computer users rely on their operating system to manage the printer. Ideal black and white prints are not made this way. Instead, a “profile”, provided by the printer or ink manufacturer is required.
ICC Profiles – “Photo-realistic” printers average out subtle colour values to produce photo-like pictures. A detailed colour image is reduced to relatively few colour print values: fine for most uses, but not necessarily accurate. A monochrome print cannot offer the viewer the extra data in terms of colour to help them interpret the image, so a more demanding standard is required.
The solution is to ensure that the correct profile is installed. ICC (International Colour Consortium) profiles represent the colour space of each ink, printer, monitor or capture device. Every device that captures or displays colour will have its own profile. ICC profiles, when written for a calibrated, stable ink set/media combination, result in each individual subtle variation being faithfully reproduced in your print.
Some manufacturers provide profiles for their products which can be downloaded from their web sites, and there are several products that allow end users to generate their own colour profiles. The correct profile should allow the reproduction of all the tonal values from extreme black to specular white, with full fidelity in the mid tones.
ICC print profiles allow you to send your files to other print professionals, knowing that if they are also use good quality ICC print profiling, their prints should match yours.
Good Black and White with Colour Inks – Even with the right profile enabled, ink jet printers are designed and optimised for colour printing. With a little care, they can be “re-optimised” for monochrome. To do this, you need to make some adjustments in the print driver software. By saving those adjustments under a distinctive name (like B&W) you can switch between colour and black & white settings whenever you wish.
The specific steps below are for Epson printers but they are similar for other printers.
Open the application you normally print from (once the corrections are made, they will work from all your applications) and select File/Print to get to the settings for the driver. Choose the correct paper type and then click on Custom, which will display an Advanced button. Click it.
First make sure that you choose high quality and turn high speed printing off.
Under colour controls you'll have the option of fine tuning the output of the printer.
Gamma - Controls image contrast by modifying the mid tones and mid level greys.
Mode - Automatic provides output that closely matches the original image. Photo-realistic increases the contrast of the output. If there are contrast problems choose Automatic and adjust the contrast manually.
Individual Controls allow you to adjust brightness, contrast, saturation, and colour to match your original. Use the colour controls to eliminate colour casts and brightness, contrast, and saturation to match the output to your screen.
RGB vs. Lab Colour Space - a straight conversion to grey scale, no matter what method you use, gives you an image that looks a bit muddy and drab and generally lacks punch. This is because RGB and CMYK colour spaces combine colour and brightness information.
A better choice for some black and white work can be LAB colour space, which separates colour and brightness information - Convert your image from RGB to LAB mode, then open the Channels palette and delete the A and B channels. Your image will now look brighter and your mid-tones will have more punch.
Convert the image back to grey scale for printing - always print in RGB. Your ink-jet printer driver does not process CMYK or Greyscale mode as efficiently.
Before you Print -
- Orientate your print to portrait or landscape format before going to print. The fewer tasks you ask the print driver to perform, the faster your print will be.
-Often, extremely subtle adjustments are all that is required to optimize your printed image. Remember that your printer is very sensitive to small changes, whereas your monitor may only show larger adjustments due to the nature of monitors.
A Dedicated System – You may want to dedicate a printer for black and white, rather than use your existing one and changing the Ink set for mono prints.
This is not as expensive as it sounds. There is an additional cost in using one printer: each time you change between colour and black inks, you have to flush the old ink out of the printer. That can add up to a lot of ink if you switch frequently, and ink is the most expensive part of your printer set-up.
You can purchase black ink cartridges that replace the colour cartridges for major printers. You can also replace your cartridges with a system of tubes that feed ink into your printers from external ink bottles. While more expensive initially, they are the most economical approach if you do a lot of printing.
