Many people buy and sell trading cards using mail, which means they need hundreds of stamps to send cards their merry way properly and safely. So, how many stamps do you need to mail trading cards?
How many stamps you need to mail trading cards depends on the number of cards per mail. Everything under one oz (28.35 g) requires one First-class or Forever stamp. For trading cards, that’s around nine cards per envelope. Everything over one oz means additional stamps and a bigger package.
If you need to mail some trading cards, but it’s your first time doing it, then you’re in the right place. In this article, I’ll discuss how many cards you can send on one stamp and what happens if you need to send a bigger stack of cards. I’ll also cover how to send your cards through the mail properly.

How Many Trading Cards Can You Mail on One Stamp?
Deciding how many stamps you need to mail anything can sometimes be confusing, especially when there are many rules and procedures. Plus, you constantly hear words like “First-class,” “non-machinable,” and “Flat mail” when all you want to do is send a few trading cards through the mail.
USPS, a go-to mailing service for many trading card dealers, has specific stipulations around weight and height when sending something. This will also affect how many stamps you need per envelope or package.
According to USPS, one First-class or Forever stamp covers one oz (28.35 g) of weight. Currently, First-class stamps cost $0.60 for standard envelopes, so it’s a relatively inexpensive way for many card dealers to mail their cards to customers or friends.
Therefore, if your stack of cards weighs more than one oz (28.35 g), you’ll need to add additional stamps to cover the exceeding weight. For instance, if your cards, including the package, weighs two oz (56.70 g), you’ll need two Forever stamps for $1.20.
This means you’d be able to send anywhere from seven to nine trading cards on one Forever stamp in a standard envelope. That many cards weigh around one oz (28.35 g). However, the number depends largely on how much protection you add for each card, as the more protection it has, the more space it takes up.
Did you know you can sell Forever stamps for more than their face value? I have an article highlighting how to sell postage stamps at face value. You should check it out for more information: Can You Sell Postage Stamps for More Than Face Value?
Now, let’s discuss the factors that may affect the price and number of stamps you’ll need when sending trading cards.
Card Protection
As mentioned, the more protection you add to each card, the less space you’ll have for them in your envelope or package. Yet, some cards require extra protection because they’re rare and expensive.
In the end, however, you’re limited to one oz (28.35 g) if you only want to send the cards on one Forever stamp.
Here are the common protective materials professional trading card dealers use:
- Penny sleeves
- Top loaders
- Tape (especially painter’s tape because it isn’t as sticky as scotch tape)
- Graded card sleeves
- Bubble wraps
- Cardboard pieces
You have a lot of material to choose from for protecting your cards, and some offer more protection than others. However, which protective material you pick will depend on the type of “container” you choose for your trading cards, which leads us to our next section.
Plain White Envelopes (PWE) vs. Bubble Mailers
Whether you want to send some trading cards to your friend or a buyer, you’ll always need to take into consideration if your cards are:
- Valuable
- Rare
- High-quality.
The two common methods of sending trading cards are plain white envelopes (PWE) and bubble mailers.

If you don’t want to damage your trading cards in any way because they’re expensive, which would mean a lower price (and usually a bad review on the e-commerce site), the safest option is to use bubble mailers.
They offer far greater protection than PWEs because they’re usually lined with bubble wrap inside, hence the name. However, USPS counts bubble mailers as large envelopes or Flats since they’re larger (over 6-⅛ in or 15.55 cm) in height or 11-½ in’ or 29.21 cm in length. This means you’d need to pay $1.20 for one oz (28.35 g) stamp as of the writing of this article.
On the other hand, you can send your cards with a PWE in these instances:
- Your trading cards are cheap
- You don’t care if they get bent during the mailing process.
Most trading card dealers look down upon those who send cards in PWEs, as they just don’t offer any protection for your cards. That’s why many send their cards in PWEs only when cards are inexpensive.
Moreover, before PWEs are sent out from the local postal offices, they pass through processing machines. This means many PWEs get partially damaged or bent in the process. So, if you have an expensive trading card, it’s not the best idea to use standard PWEs.
Finally, if you’re using PWEs, you’ll inevitably need to use more protective material for your cards, such as top loaders, which can’t bend easily. Unfortunately, top loaders usually take up a lot of space, meaning you’ll need to put in less than nine cards per PWE for one Forever stamp. Of course, you can always add extra stamps for extra weight.
Sending Cards in Boxes
You might think by now: “That’s all great, but I have to send over 50 cards! I can’t put them all in one bubble mailer!” Many card dealers usually mail well over 10 cards at once to one customer. In those cases, it’s best to use various boxes and packages rather than envelopes.
The most important thing is to use sturdy boxes and fill them with protective material like bubble wrap. You’ll also need to measure your package since there are some limitations if you’re sending it with USPS. You’ll need to calculate the following:
- Width
- Length
- Height
- Weight (maximum 70 lbs or 31.75 kg)
A package shouldn’t exceed 108 in (274.32 cm) when you combine the first three factors from the list above. USPS has a useful video on how to measure your package precisely:
You Might Need To Use Non-Machinable Stamps
You should measure your package correctly because if you don’t, you’ll need to pay a non-machinable fee, which is also a common issue with sending trading cards with PWE.
Since all packages and envelopes need to go through a processing machine, some get stuck before they’re processed. This happens because the contents of an envelope are either too bulky to pass through the machine’s slot or weirdly shaped and rigid.
When one of those two things happens, your mail becomes “non-machinable.” You could buy a non-machinable stamp (currently for $0.99) to avoid this predicament.
USPS set limitations for the thickness of standard envelopes, which is ¼ in (0.64 cm) maximum. Since some trading cards can be thicker, especially when you put them in top loaders, PWEs might not be the best way to send them in.
That’s why sending about nine cards per envelope or mailer is best since the shape of the mail remains pretty much the same. Plus, you’ll only use one Forever stamp, which is cheaper than a non-machinable one.
How Do I Send a Trading Card in the Mail?
Since one trading card weighs less than an ounce (28.34 g), you’ll need only one Forever stamp. Depending on the card’s value, you can send a card in a PWE or a bubble mailer. However, before sending it in the mail, use a penny sleeve or cell sheet and a top loader for extra protection.

Preparing the Cards for Mail
Once you have your PWE or a bubble mailer ready, it’s time to prepare your cards for mail:
- Put a card in a penny sleeve.
- Place the card in a top loader.
- Take painter’s tape and seal the top loader’s opening. Don’t touch the card.
- Divide your cards into cell sheets equally. For nine cards, you’ll have three cell sheets with three cards in each.
- Place the cards in a PWE or a bubble mailer.
- Weigh the package. It should be below one oz (28.34 g).
- Write down the necessary postal information and stick one Forever stamp.
Note: If it’s more than one oz (28.34 g), you’ll need to use Additional Ounce Stamps that currently cost $0.24, another Forever stamp, or Partial stamps.
Final Thoughts
The number of stamps you’ll need to mail your trading cards depends on the number of cards you’re sending and the quality and protection you want for them.
You can send around nine cards in a PWE on one Forever stamp, as one stamp covers one oz (28.34 g) of weight per package or mail. However, PWE doesn’t offer additional protection for your cards.
If you’re mailing more expensive cards, use a bubble mailer for extra protection. Remember, if it’s more than one oz (28.34 g) in weight, you’ll need to add a stamp for extra ounces.