On Aug 8, 2005, at 5:15 PM, Mike Watkins <watk5926 at bellsouth.net> wrote:
> Marta, > > Jerry Yeager told me once that our printers mix several colors with > the > black ink to print black. I forgot why he said it works that way. Mine > does the same thing. Jerry's a wise man... I have a poor memory for > details. > > Mike As a guy who has inhaled a few of the solvents used in offset printing in his day, I'll weight in on this one. Since you cannot vary the amount of ink across the sheet with any serious degree of accuracy (although some presspeople can sometimes work magic) the amount of ink slapped on a sheet of paper is not enough to give you a nice dense black. What happens is that the black, which is usually trying to cover a really white white, gets stretched a little thin and ends up looking very flat. If you put too much ink on the rollers so that it transfers to the plate and thus to the paper, that same ink will be too heavy in others areas as well. That means your photos will be too dark and any other mixes that include some black will be shifted to the dark side. What offset printers will do is to add some magenta and/or cyan into the screening. They end up laying 40 to 60 percent dots of magenta and cyan under the black (black usually goes down last on the press). That will give you what is called a "rich black." You can vary your magenta and cyan (and no two people prefer the same mix) depending on whether you like a cold black (bluer) or a warm black (redder). This is for offset printing mostly. In the high quality "photo" setting for your printer, there will be some color mixed in with the black to make it richer also. But even if you set your printer for low quality black only it will still not print with an empty light cyan cartridge for one simple reason. Anybody who has ever purchased a set of ink cartridges that bargain basement mechanical marvel will know that reason in their soul: The printer manufacturers don't make their money on the printers. ::-\ j. -- Jonathan Fletcher jfletch at newmediaconstco.com | The next meeting of the Louisville Computer Society will | be August 25. The LCS Web page is <http://www.kymac.org>. | List posting address: <mailto:macgroup at erdos.math.louisville.edu> | List Web page: <http://erdos.math.louisville.edu/macgroup>
