My partner and I are trying to set up the card size and design on it, it depends on which angle we use, which is likely to be over-the-shoulder shot so we did a test round to see how each card Works.
First one: printed template 7cm x 5 cm
This one is bigger than the First one and the paper is thicker and tougher.
This is the three sizes we tried and we decided to choose the second one (medium) that is suitable for filming:
We also tried vertical direction but I realized that the camera goes with landscape(horizontally):