The Flippin’ Men card is a triple fold aperture card which has a 3mm spine to protect the front & back decoupage, which sits either side of a piece of acetate in between the two apertures.

 
Lay the card out flat so that the inside of the card is facing up.

Stick a piece of acetate (large enough to cover the aperture) over the central aperture using double sided tape.

Now place some 3mm thick foam pads around the outer edges of that central panel.

(One in each corner and one in the middle of each side should suffice)

Take the backs off the foam pads & fold the end aperture panel over the central panel, aligning the apertures, so that one is directly on top of the other.

Once you have the apertures aligned, press the two panels together.

By using 3mm thick foam pads to stick the two panels together, you will keep the 3mm spine in tact so that it can protect the decoupage inside the aperture.

Your Flippin’ Men front & back decoupage image sits on either side of the acetate inside the aperture.