I've been asked to give dimensions for the easel cards. They are really easy and don't require that they all be the same size. The important thing to know is that the card base is twice the length of the card top. They are the same size wide so that when the base is folded in half it is the exact size as the top.
For example for a 6x6 card you will need top to be 6x6 and the base to be 12x12.
Or for a 4x6 card, top us 4x6 and base is either 4x12 or 8x6 depending on which direction you fold it.
Then you fold the base in half, then the front of the card in half again (see photos). This makes the easel stand. Then glue the card top to the bottom fold of the base. Hope this is clear as mud. Lol!