Do Wax Seals Hold Up in the Mail? We Find Out

Wax seals actually date back to the Middle Ages. However, you don’t need to be a 16th-century squire, a guild obermeister, or the president of the United States to use them. Both seals and wax are easily accessible and add a little class to your mail, especially invitations or memos.

But is this pomp and circumstance going to hold up in the global postal system you ask yourself? Long gone are the days of Kevin Costner walking hundreds of miles to deliver you an important letter. These days it’s freight trains, planes, and automobiles that are needed to service the millions of bills, cards and other communications sent every day.

Your mail is going to pass through many more hands with undoubtedly less care taken than when wax seals were at their height and that’s without the introduction of 21st-century machinery! So, how can you be sure that they’ll survive their passage? Well, that’s where we at Flame Stuff come in. We have conducted a little experiment to see how modern-day wax seals fare, posting letters both domestically and internationally. Keep reading to discover if, in fact, wax seals survive in the mail!

Sealing wax requires flexibility to have a chance of surviving 21st-century mailing procedures. Resin can be added to optimize flexibility. Choosing the correct wax to seal your correspondence will give you the best chance of it completing its journey intact.

History of the Wax Seal

Some of the very earliest civilizations known to man used seals. Authentic specimens have been found proving that they were in use by both the Indus Valley civilization from the Bronze Age and the Mesopotamia civilizations. These civilizations date back to some 3,000 years BC. Seals are certainly no new phenomenon!

However, these original seals were made from clay. Wax didn’t come into practice until the Middle Ages and was predominantly used by the elite such as prominent church officials, Kings, Queens, and royal spokespeople.

As we headed into the 1400s their use became more widespread until eventually, even regular citizens were using them. As the 16th century approached and emigration and colonialization became more widespread an upsurge in written communication lent more popularity to the use of wax seals.

During the Middle Ages, sealing wax was made from a mix of resin and beeswax although more distinguished users preferred more exclusive materials such as a form of lead called bulla.

Today sealing wax is predominantly made from paraffin wax with added resin, which adds flexibility, or shellac which hardens without leaving any oily deposits. Coloring tints are also added to many waxes to offer a wider choice to the buyer. 

Why Wax Seals?

Seals had more than one purpose. Like fingerprints, a seal, wax, or otherwise, was unique to the user. For the higher-ranking members of civilization, they were used as a means of authenticating documents.

However, the extremely excessive levels of illiteracy within society at the time of the height of wax seals meant that they were used in place of a signature or ‘X, the mark of’.

Cost was also a factor by the time we reached the mid-1800s. Sending a letter was an expensive business and postage was calculated on the quantity of parchment used rather than weight. This made it cheaper to fold and seal over using envelopes which came at a premium. Envelopes were a luxury only afforded to the rich!

With the improvement of envelope manufacture in the mid-19th century, especially the gummed variety they became more accessible to the general public and the demise of the wax seal commenced.

Until today that is, the resurrection of this timeless, nay classic method, adds that touch of both class and elegance to any correspondence, keeping alive the memories of days of yore.

How Do you use a Wax Seal?

In days gone by wax was pressed with either a handheld seal or a signet ring. Whilst we still use a handheld seal today a signet ring has largely been left to history. Methods for melting the wax have also changed over time although using a flame just like your ancestors, is still an option.

You will need wax and a heat source as a minimum. The heat source can be, as already mentioned, a traditional flame in the form of a candle or tealight, a wax melter, or a heat gun.

NB: Wax is always reusable. Mix different colored used seals together to create unique seals and marbled effects.

Traditional Sealing Wax with Wick

If you are using the traditional method, a sealing wax stick with a wick, you will need to hold your lit stick at a 20° angle allowing the wax to drip on the area you wish to seal. Emboss using your handheld seal, holding it straight and moving slowly.

Glue Gun Sealing Wax

You can also use a glue gun. You will need to insert the wax stick into the glue chamber. Once the gun is up to heat pull the trigger to deposit the wax between ¾ and 2 full pulls depending on the size of the seal you are using.

You will need to wait between 10 and 15 seconds before you emboss with your seal using the same straight and careful method. Trail and error will be required to determine how deep / often to pull your glue gun trigger and how long you will need to wait before embossing.

Melting Spoon Sealing Wax

If you are using a melting spoon, place your wax (either beads or portions of wax sticks) into the spoon and your heat source underneath. Be careful not to melt the wax too much, if it becomes too thin, spread is a risk and you will struggle to achieve the seal you were hoping for. The texture you require can be likened to cold honey.

Pour the wax onto your project and emboss with your seal as above. As with the glue gun method, trial and error will be required for timings between pouring and embossing in order to create an enhanced definition in the stamp and avoid thinning of the wax.

How to Post: Mailbox or Post Office?

Our research shows that there is no ‘one rule fits all’ when it comes to the USPS. Individual Post Offices seem to have their own distinctive procedures, even if only subtle.

It is worth noting that whilst USPS allows envelopes and even parcels to be sealed with wax the closure itself must be “sufficient to allow detection of tampering”.

When USPS sorts your mail for its onward journey it, depending on its size, goes through a machine that ‘cancels’ the postage. This means that your stamp is printed over to stop people from using stamps more than once. Whilst this is an efficient method for USPS it doesn’t help your wax seal if the envelope is too thick.

To avoid any damage by the canceling machines we would always advise that anything you have wax sealed is taken to the Post Office so that hand canceling can be arranged.

Inside or Outside?

Inside or outside, the choice is yours. Sealing your correspondence, whether that be a letter, a memo, or an invitation, and then placing it inside a modern-day gum-sealed envelope will lower the risk of damage significantly.

However, will that spoil the effect? Is it worth the gamble to ‘show off’ your beautiful stationery allowing for full visibility at each stage of the mailing process?


Relatively risk-free in terms of the mailing system you may choose to seal your project and then use a contemporary envelope to send it.

Do be aware that the seal may still be affected by the postage canceling machines if the envelope is too thick. It would be worth still taking your letter to the Post Office and speaking with the staff to determine the best mode of transit than just dropping it into a mailbox.


If you’re going to take the risk, then ensure you take as many precautions as you can to avoid the seal being damaged in the mail:

  • Don’t overfill the envelope, in fact, try to limit the contents to one piece of parchment.
  • Use the thinnest type of envelope.
  • Check with your local Post Office with regard to their hand-canceling policy. Hand canceling will prevent your letter from going through the machine, preserving the seal.

You can seal the envelope itself by using your wax and stamp. However, the alternative is to bulk make your seals in advance and glue them to the envelope after sealing in traditionally with the gum strip. As wax seals are for decorative purposes in the modern world the latter option is perfectly acceptable.

Do Wax Seals Stay on in the Mail? Our Conclusion

We conducted our own experiment to find out if wax seals, do indeed, stay on in the mail.

We followed the melting spoon method of wax sealing our letters, stamped them on the outside, and took them to the post office to be weighed and stamped.

It’s not the neatest but it’s ready to go!

Our test was UK based on this occasion where there is no option of hand canceling so both our domestic and international envelopes went through the franking machine as part of their journeys.

International franking
Domestic franking

Whilst our envelopes only contained a basic letter on the inside we are pleased to report that yes, for both international and domestic postage wax seals DO hold up in the mail!

Internation wax stamp upon delivery!
Domestic wax stamp upon delivery!

Related Questions

How to Open a Wax Seal Letter

Whilst heat is the energy source needed to seal your wax cold is what is required to open it again causing the least damage.

Pop your letter in the freezer for 30 minutes or so and then slide a thin knife or letter opener under the seal until it pops off. Of course, you can do this without the freezer element of the process, but you will need to be extra careful not to break or damage the wax.

Alternatively, you can also open the envelope along the top, also using a sharp knife or letter opener. Once the letter has been removed use scissors to cut the seal away. Of course, this will leave part of the envelope stuck to the back of your seal.

You may also be able to peel off the wax seal, but this will take great care and patience and is not advisable if you are hoping to keep the seal intact.

It is possible to reseal by heating the back of the seal briefly with a lighter or candle and pressing it back down onto the envelope. 

Best Envelopes for Wax Seals

Parchment paper is the best material for wax seals if you are bulk making them in advance as they are easily removed for then gluing onto your envelope.

In today’s society, your biggest obstacle is the machinery used by the USPS. The wax seal is going to make the envelope thicker and therefore potentially jam in the machine. This is going to both ruin your seal and rip the envelope, not the outcome you’re after!

Anything over .25” thick is a parcel in the eyes of USPS. Now, this is going to up the postage cost but it’s worth the extra few dollars to post as a parcel, rather than a letter to keep your correspondence pristine.