# Page Not Found

The URL `en_US/print_mail/mail-piece-design-formats` does not exist.

You might be looking for one of these pages:
- [Mail piece design specs](https://help.lob.com/print-and-mail/designing-mail-creatives/mail-piece-design-specs.md)
- [Letters](https://help.lob.com/print-and-mail/designing-mail-creatives/mail-piece-design-specs/letters.md)
- [Custom mail](https://help.lob.com/print-and-mail/designing-mail-creatives/mail-piece-design-specs/custom-mail.md)
- [Letter add-ons](https://help.lob.com/print-and-mail/designing-mail-creatives/mail-piece-design-specs/letter-add-ons.md)
- [Postcards](https://help.lob.com/print-and-mail/designing-mail-creatives/mail-piece-design-specs/postcards.md)

## How to find the correct page

1. **Browse the full index**: [/sitemap.md](https://help.lob.com/sitemap.md) - Complete documentation index
2. **View the full content**: [/llms-full.txt](https://help.lob.com/llms-full.txt) - Full content export

## Tips for requesting documentation

- For markdown responses, append `.md` to URLs (e.g., `/print-and-mail/designing-mail-creatives/mail-piece-design-specs.md`)
- Use `Accept: text/markdown` header for content negotiation