A letter ledger, for you to keep track of your ingoing and outgoing correspondence.
Document the essentials (if you have such a letter-writing regimen):
1. The date you receive a letter, and the details you wish to remember from it
2. The items you plan to highlight in your return letter, and the date you send it
3. The bit of card or stationery you used for your reply
On the inside front of the ledger is a small envelope to keep hold of postage, and at the back, some space to note names and addresses of frequent correspondents.
+Kraft cover with white writing paper
+84 pages (for just over 500 entries)
+Ships in a rigid mailer