Removing Moiré Effectively - Page 5
On the original version of the file, make the "a" channel active in the "Channels" palette. Choose Filter>Blur>Average. Do the same for the "b" channel.
Using Gaussian Blur sometimes leaves large, indistinct swirls. These will show up as slightly colored areas that require some additional attention. With the addition of the "Average" filter, I no longer use Gaussian Blur for this technique.