I hadn't heard of the word "moiré" before, meaning to have a watered or cloudy appearance, as in silk or metals. Someone sent me this fun site about moiré patterns.

Moiré patterns are a real problem when you're trying to reprint pictures made up from pixels (such as a magazine picture), using a system that also uses pixels. The moiré patterns formed can be very disturbing although most photo-editing programs have a moiré pattern reduction utility which helps.

In fact, the pattern is typically of lines, often curved, and not milky or cloudy.

Hehe. I like it .

Pixels usually refer to the picture elements of a CRT or similar computer display. Older print technologists spoke of halftone dots, measured in lines per inch. Similar but different, even though I'm sure the meanings are slowing changing. It is inevitable.

http://en.wikipedia.org/wiki/Halftone
http://en.wikipedia.org/wiki/Pixel

Interesting discussions, Zmj, and I hadn't known that pixel was a portmanteau of picture element. I learn something new every day!