The static grain effect?

It's pretty easy. I found a grain texture online, set it to Overlay at 35%.

Frame 1: save as image 1.

Frame 2: flip grain layer vertically; save as image 2.

Frame 3: flip grain vertically (back to normal) but flip it horizontally; save as image 3.

Frame 4: flip grain layer horizontally (back to normal), then flip it vertically and then horizontally; save image 4.



Pretty much, each of the 4 images has a differently oriented grain layer, so when I make it into the gif, it loops without any repeated frames.