Dag, While I would normally agree with Tom, regarding your following comment, visually there IS no pair, unless you can distinguish between each line.
[EMAIL PROTECTED] wrote: > > > Fra: mike wilson <[EMAIL PROTECTED]> > > > > Tom wrote: > > > However as far as I know line pairs > > > consist of two lines with a space in the middle, when the space > > > disappears you have hit the limit of resolution. <grin> > > So this pair consists of three things.......... No, two 'things,' or two individual items, if you will. One item is a black line. The other item is a white line. Separate the two black lines with a while line in between, and you have a pair of black lines. This assumes all you start with is two black lines on a piece of white paper. If you insist on making one of a "pair" of lines white, then the background or the sheet of media on which they lie MUST be of a contrasting color, in order to tell that the "white line" is not merely a space between two black lines. > Imagine a pair of objects with no separation between them. Is this a pair or is it > one object? > > Beyond the resolution limit there you see one line, not two separate lines. > > :-) > > DagT If, as Rod has most recently exposed us to, you define a "line pair" as two CONTIGUOUS lines, meaning adjacent to and touching each other, they MUST be of different contrast, or you wouldn't be able to distinguish that there were two of them... In Rod's supplied definition, it can indeed be a white line and a black line, sharing a common border. That's when you need the media upon which they reside to be a third shade or color. Interesting discussion... keith
