Before we start talking about how we can reduce and eliminate moiré [mwah-rey], let's first make sure you know what it is and what kinds of
The only thing common about all kinds of moire is the fact that it's a wavy pattern that looks as if it should not be where it is. It occurs due to the interference of fine patterns – be it pixels of a camera sensor or garments material. I'm not going to bore you with theoretical information, let's just keep it short and meaningful.
Sometimes, when a camera takes pictures, it can produce a weird-looking wavy pattern. These patterns do not appear randomly. When you see moire on the images, you can be sure that there's some fine pattern present. And when this fine pattern on your item meets with the fine pixel pattern on the camera sensor, a third pattern appears. This is called the moire effect, and it's a pain to remove it from images during retouching. But that's not all there's to it. There are a few reasons why moire can appear, and there are also a few ways how to eliminate it. The deal is that all the moire removal methods are useful only on particular kinds of moire. If you don't understand what's going on, you might waste a lot of time and effort.
It's not like there's a book where all kinds of moire are listed. I just used whatever names I could think of while trying to reflect the nature of moire. So don't be surprised if you can't google “true moire” or “interpolation moire”. But I hope that after you finish this chapter, you won't need googling, as I tried to make it as full and comprehensive as I could. Pay attention to the fact that I haven't invented any of the methods I will be explaining, and I will try to mention their authors whenever I can pinpoint them.