I received this gorgeous Pocket Page letter from a penpal Gina. Pocket Page Letters are based on the ATC sizes and uses the same pockets. This craze was started by Janette Lane. You can send these to penpals. and include a letter in one of the pockets or if your letter is too big to fit in there then just add it to the parcel when posting.
Gina and I write long letters so they don't fit into a pocket.