---
type: guide
title: "A Guide to Pairing Postcards and Envelope Sizes"
description: "Pair every standard postcard size with the right envelope: A2, A6, A7, and A9 matches, USPS size rules, and a clear postcard-to-envelope chart."
resource: https://www.4over4.com/guide/a-guide-to-pairing-postcards-and-envelope-sizes
tags: ["guide"]
timestamp: 2026-07-20T18:54:40.856Z
---

# A Guide to Pairing Postcards and Envelope Sizes

Pair every standard postcard size with the right envelope: A2, A6, A7, and A9 matches, USPS size rules, and a clear postcard-to-envelope chart.

See [all guide concepts](index.md).

- Page type: guide
- URL: https://www.4over4.com/guide/a-guide-to-pairing-postcards-and-envelope-sizes