Photo Editing for B&W or One Colour Printing

Do you use scanned photos or digital pictures in your black and white or 1 colour printing? If so, there are a few things you should know. Although its impossible to cover all the scenarios you might face, if you follow the four steps presented here, you'll achieve great results with your black and white images.

1) Save a copy of your original file. Even experts in image editing usually don't get it right the first time. Back up your original image, because in a high percentage of cases, you'll need it.

2) Convert colour images to black and white While it's not always necessary to convert your images to black and white before printing them, it's always a good idea. Often, an image that looks like it has lots of contrast in colour can look horrible in black and white. For instance, if you had a colour image that had lots of reds and blues contrasting against each other, you might find that they were both the equivalent of 60% gray when printed in black and white - leaving you with no contrast at all. If you do have a situation as described with the red and blue above, you can go back to your original colour image (you saved a copy, didn't you?) and use the colour channels to artificially create contrast that will carry over to the black and white. If you had a CMYK image and used the example above, removing yellow from the image (from the yellow "channel") would lighten the red, leave the blue unaffected, and create contrast for you in the black and white image. Of course, this adjustment may change your green grass to a light blue, but it likely won't matter after the conversion to black and white.

3) Adjust your brightness and contrast When you adjust your brightness and contrast, make sure to leave some "dot" in the lightest area. Basically, what you want to do is leave at least a few percent gray tone throughout your images so that they look natural. The amount of "dot" you need may range from 3% gray if you are doing super-fine quality offset printing to 15% or more for some copiers and digital printers. The reason for leaving or adding gray to your image is that one colour or black and white images usually look very unnatural without any tone. This is something you see in black and white images of people's faces, often making foreheads and the bridges of people's noses contrast too strongly to the soft adjacent tones of the face.

4) Adjust your output levels if necessary In cases where there is simply no dot at all in vital areas, you can compensate for this by adjusting the output levels in your images (in PhotoShop this is found in "levels"). To arrive at your ideal output levels if you need to add "dot"(ask your printer what the minimum grayscale percentage should be), multiply the necessary grayscale value by 2.5 and subtract that number from 255. For example, if you need a 10% minimum dot, you would set a 230 output level (10x2.5= 25, 250-25 =230).

The above steps should give you the basics you need for adjusting black and white images. If you've got some great tips of your own, share them with us at This e-mail address is being protected from spambots. You need JavaScript enabled to view it '; document.write( '' ); document.write( addy_text33641 ); document.write( '<\/a>' ); //--> This e-mail address is being protected from spambots. You need JavaScript enabled to view it and we'll try to include them in a future update or article. See you next month!