Flip-flop effect is made by 2D/3D master shooting system. It's also called two channel effect of 2D/3D. Flip-Flop hologram
can display two images from different viewing angle. When the viewing angle changes horizontally (left to right) or vertically (upside and down),
different images evolve through the hologram.
Flip-flop hologram has two or three hologram images or text flips in one position
with big different viewing angle. So one hologram image will mask and another
hologram image will display when you change the view angle a little bit.

Holographic sticker which has flip-flop effect.The letter 'L' and ''S is flip-flop

Holographic sticker which has flip-flop effect |