Envelope Size Guide: DL, C5, C6 Explained
Envelopes might seem like a simple item, but choosing the right size can make all the difference when it comes to presenting documents, sending invitations, or posting correspondence with a professional touch. This guide explains three of the most commonly used envelope sizes—DL, C5, and C6—offering insights into their dimensions, uses, and tips for selecting the best option based on your needs.
Whether you’re planning a large event, running a business, or simply sending a greeting card, understanding envelope sizes will help ensure your content is delivered in style.
What Are Envelope Sizes?
Envelope sizes in most countries follow the ISO 216 format, which is a global standard for paper sizing. These dimensions—often marked as A, B, or C series—simplify the process of pairing envelopes with paper sizes. For example, paper from the A series (like A4, A5, etc.) is perfectly compatible with corresponding C series envelopes, offering a snug fit.
This guide focuses on three popular sizes in the C series—DL, C5, and C6—to help you decide which is most suitable for your needs.
DL Envelopes: Sleek and Professional
Dimensions
A DL envelope measures 110mm x 220mm. It is long and narrow, fitting a standard A4 sheet that has been folded into thirds.
Common Uses
DL envelopes are a staple for business correspondence. Given their sleek and professional design, they are widely used for:
- Sending invoices and bills
- Sales letters or promotions
- Contracts or formal client communications
Their compact size ensures low postage costs while offering enough space for basic documents. If you’re distributing event invitations or newsletters and want to add a professional touch, DL envelopes are an excellent choice.
Tips for Selecting a DL Envelope
Choose DL envelopes with a protective window if you’re posting printed letters featuring recipient details. This saves time and ensures clarity for the reader. For added impact, consider a coloured or textured finish to match your brand or event theme.
C5 Envelopes: Roomy and Versatile
Dimensions
A C5 envelope measures 162mm x 229mm, making it large enough to hold an unfolded A5 sheet or an A4 sheet folded in half.
Common Uses
C5 envelopes are highly versatile and commonly used for:
- Sending magazines or booklets
- Invitations with RSVP cards
- Legal or official documents requiring a larger, flat surface
- Greeting cards that need a little more presentation space
Their roominess ensures your posted contents look crisp and professional, avoiding the need for heavy folding.
Tips for Selecting a C5 Envelope
Opt for a heavier GSM (grams per square metre) material if you’re posting booklets, catalogues, or multi-page documents. This ensures your contents stay intact and presentable during transit. Peel-and-seal closures are a practical and secure choice, especially for business use.
C6 Envelopes: Perfect for Personal Messages
Dimensions
A C6 envelope measures 114mm x 162mm, accommodating an A4 sheet that has been folded twice (into quarters) or a flat A6 sheet.
Common Uses
C6 envelopes are commonly found in personal stationery collections and are perfect for:
- Sending greeting cards
- Individual thank-you notes
- RSVP responses
- Event invitations with minimal inserts
Their compact size and versatility make them ideal for both personal and light professional use.
Tips for Selecting a C6 Envelope
If you’re sending greeting cards or invitations, opt for designs with decorative or unique finishes to make the envelope immediately stand out. Lighter colours work great for formal occasions, while brighter tones can match festive events
-
Envelopes might seem like a simple item, but choosing the right size can make all the difference when it comes to presenting documents, sending invitations, or posting correspondence with a professional touch. This guide explains three of the most commonly used envelope sizes—DL, C5, and C6—offering insights into their dimensions, uses, and tips for selecting the best option based on your needs.
Whether you’re planning a large event, running a business, or simply sending a greeting card, understanding envelope sizes will help ensure your content is delivered in style.
What Are Envelope Sizes?
Envelope sizes in most countries follow the ISO 216 format, which is a global standard for paper sizing. These dimensions—often marked as A, B, or C series—simplify the process of pairing envelopes with paper sizes. For example, paper from the A series (like A4, A5, etc.) is perfectly compatible with corresponding C series envelopes, offering a snug fit.
This guide focuses on three popular sizes in the C series—DL, C5, and C6—to help you decide which is most suitable for your needs.
DL Envelopes: Sleek and Professional
Dimensions
A DL envelope measures 110mm x 220mm. It is long and narrow, fitting a standard A4 sheet that has been folded into thirds.
Common Uses
DL envelopes are a staple for business correspondence. Given their sleek and professional design, they are widely used for:
- Sending invoices and bills
- Sales letters or promotions
- Contracts or formal client communications
Their compact size ensures low postage costs while offering enough space for basic documents. If you’re distributing event invitations or newsletters and want to add a professional touch, DL envelopes are an excellent choice.
Tips for Selecting a DL Envelope
Choose DL envelopes with a protective window if you’re posting printed letters featuring recipient details. This saves time and ensures clarity for the reader. For added impact, consider a coloured or textured finish to match your brand or event theme.
C5 Envelopes: Roomy and Versatile
Dimensions
A C5 envelope measures 162mm x 229mm, making it large enough to hold an unfolded A5 sheet or an A4 sheet folded in half.
Common Uses
C5 envelopes are highly versatile and commonly used for:
- Sending magazines or booklets
- Invitations with RSVP cards
- Legal or official documents requiring a larger, flat surface
- Greeting cards that need a little more presentation space
Their roominess ensures your posted contents look crisp and professional, avoiding the need for heavy folding.
Tips for Selecting a C5 Envelope
Opt for a heavier GSM (grams per square metre) material if you’re posting booklets, catalogues, or multi-page documents. This ensures your contents stay intact and presentable during transit. Peel-and-seal closures are a practical and secure choice, especially for business use.
C6 Envelopes: Perfect for Personal Messages
Dimensions
A C6 envelope measures 114mm x 162mm, accommodating an A4 sheet that has been folded twice (into quarters) or a flat A6 sheet.
Common Uses
C6 envelopes are commonly found in personal stationery collections and are perfect for:
- Sending greeting cards
- Individual thank-you notes
- RSVP responses
- Event invitations with minimal inserts
Their compact size and versatility make them ideal for both personal and light professional use.
Tips for Selecting a C6 Envelope
If you’re sending greeting cards or invitations, opt for designs with decorative or unique finishes to make the envelope immediately stand out. Lighter colours work great for formal occasions, while brighter tones can match festive events
Chinese
English
Arabic
French
Spanish
Portuguese
Deutsch
Turkish
Dutch
Italiano
Russian
Portuguese (Brazil)
Greek