In A PAT, you make one card for each player in your group.
In a group of 5 player, which includes you, you make 4 cards and receive 4 cards in return.
If you play in 2 groups, then you would make 8 cards, 4 for each group, and receive 8 cards in return.
The PAT host sorts the cards and fills the players return envelope with the cards that were made for them.