A bifold is just what it sounds like: paper folded into two halves. (Mandalas are folded four times, making eight surfaces.) While mandalas always come out somewhat circular in shape, bifolds can be circles, squares, oblong, triangular, egg-shaped, heart-shaped, or any number of abstract mirrored shapes. Detail can be greater, as one is cutting through only two layers of paper. Yet designing an image to fit a bifold shape can be more difficult.
To save time, I always create two bifolds at once by folding two pieces of paper together. I cut the basic shape and a few key elements, then take the papers apart and finish them separately. This way they are similar but not identical. This would not be possible with mandalas because I am already cutting through eight pieces of paper when creating them.
Shown here are the two I cut last night: a one and a half movie project.