I nearly lost a rare 1921 Morgan silver dollar last year. The flimsy plastic bag I used almost cost me $200. That's when I discovered real coin envelopes¹.

Coin envelopes are small paper containers designed to protect and organize collectible coins. They come in numbered sizes (like #4 or #7) with gummed flaps, usually made from acid-free kraft paper² to prevent metal corrosion.

But here's what most collectors don't realize - choosing the wrong envelope can damage your coins permanently. Let's break down the essentials.

What are coin envelopes used for?

I once watched a client store gold bullion in sandwich bags. Big mistake.

Coin envelopes protect collectibles during storage/shipping, organize numismatic collections, and prevent oxidation. Museums use archival-quality versions for century-long preservation.

Key applications across industries

The US National Numismatic Collection requires envelopes passing 3 tests: pH neutrality, tear resistance, and static-free material.

Can coin envelopes be mailed?

My first international coin trade ended at customs - the envelope failed basic postage rules.

Yes, coin envelopes can be mailed if under 3.5oz (100g) and under ¼" thickness. USPS requires hand-canceling³ for coins to avoid machine damage. International shipments need customs form CN 22.

Postal requirements by country

I recommend using 2-point board stiffeners when mailing silver dollars. The extra $0.15 prevents bent coins.

How do you mail coins?

Last Christmas, we shipped 5,000 custom coins worldwide. Zero damage claims. Here's how.

Use this 4-layer method: 1) Coin in 2x2 cardboard holder 2) Sealed in numbered envelope 3) Padded mailer with tracking 4) External FRAGILE labels. Insure shipments over $50.

Cost comparison: USPS vs private carriers

Pro tip: Always use "Non-Machinable" stamps ($0.40 extra) to avoid automated sorting systems.

What size is a number 4 coin envelope?

Choosing envelope sizes confused me initially. Now I specify dimensions down to the millimeter.

#4 coin envelopes measure 3.125" x 4.5" (79mm x 114mm)⁴, fitting coins up to 38mm diameter. Standard 24# paper holds 10 silver eagles comfortably.

Size chart with coin compatibility

Our factory produces custom-sized envelopes for oversized coins like 90mm Chinese Panda medals.

What size is a 7 coin envelope?

When a client needed to ship 20 proof Krugerrands, standard envelopes failed. #7 saved the day.

#7 coin envelopes are 4.5" x 5.125" (114mm x 130mm)⁵, designed for crown-sized coins up to 45mm. The reinforced construction handles 1.5oz bulk shipments.

Material thickness options

We've developed anti-static #7 envelopes with RFID blocking - crucial for high-value shipments.

Before You Go: Upgrade Your Collection

For 12 years, INIMAKER® has helped collectors and institutions preserve numismatic treasures. Our ISO-certified facility combines traditional craftsmanship with cutting-edge protection tech:

• Military-grade 18K gold plating (up to 50μ thickness)
• Patented ColorLock™ enamel (10-year fade guarantee)
• Custom RFID-embedded envelopes with GPS tracking

When the Smithsonian needed archival solutions for their 1907 Saint-Gaudens Double Eagles, our team delivered:

• 100% acid-free materials
• Custom die-cut holders
• Humidity-controlled packaging

Whether you're storing 10 silver rounds or shipping $10,000 proof sets, we handle both 100-piece trial orders and 50,000-unit bulk needs. Get your free sample kit (T&C apply) via DHL Express.

Conclusion

Coin envelopes protect value through precise sizing and material science. Choose archival-quality options for collectibles, and always follow postal guidelines when shipping. Proper storage prevents costly damage.
Contact INIMAKER® Team