Photo Prep for Copying

[joroho]

I hope I'm in the right forum for this question, please forgive me if I'm not.

I will likely be taking over a newsletter for our homeschool group and need some advice on photo preparation. The newletter is going to be printed out once on a laser printer and then photocopied multiple times for distribution. Can anyone offer advice on how best to prepare color photos for this process?

.joroho.

[Peter Clifton]

Joroho

I have a tiny bit of experience in this field.

To do this successfully you will need access to two things

1) A bitmap package capable of working in Lab mode and able to split the image into separate channels.
2) A B&W PostScript laser printer.

First, converting a colour image to B&W may seem straightforward but using the default convert to grey scale option is usually not the best way.

My preferred method is to convert the colour image to Lab mode, split image to channels and delete the a & b channels

Next preferred method is to desaturate the RGB image prior to converting to grey scale.

Least preferred method is to go from RGB to grey scale in one go.


Next printing the image.

If you output the document at the default maximum resolution of a 600 dpi Laser printer, when photocopying, bitmap images tend to take on the resemblance of a black blob, even on a first generation copy. The trick is to lower the LPI (Lines Per Inch) resolution of the printer. Normally this feature is only to be found in PostScript printers. On non postscript printers you could try lowering the DPI resolution to 300 or 150, this should also have an effect on the size of the halftone screen.

In your layout package, under options for printing, if you are using a PostScript device there should be a setting that allows you to alter the LPI setting from the default printer maximum. Most photocopiers I have used handle 60 LPI without too much trouble, good ones can go to 75 LPI or even higher. When lowering the LPI you trade off printed image resolution against a more recognisable photocopy.

Try photocopying an example printed at 60 or 75 LPI first, before increasing the LPI in the PostScript options to see if better results can be achieved with the photocopier.

HTH

Peter

[joroho]

Many thanks, Peter. I appreciate you taking the time to offer me some advice. I'll try to let you know how it looks.

.joroho.