

It can be a bit annoying when you’re looking for a good 4.5 x 5.75 envelope and can’t find an envelope with those exact dimensions.
That’s because most of these envelopes that some people call the 4.5 x 5.75 envelope actually measure 4.375 by 5.75 inches.
Sometimes they’re also called A2 invitation envelopes, except that your 4.5 x 5.75 envelope may not be part of the A-style envelope category.
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There’s also a 5.75 x 4.5 envelope that’s part of the baronial envelopes.
Other Types of Envelopes
Confused yet? To help clear up some matters, here’s a quick overview of other envelope types that you may need in the future.
Baronial
The 4.5 x 5.75 envelope is part of the announcement type of envelopes, but there’s also a baronial envelope in this size.
Most people tend to consider baronial envelopes as less formal, though they’re both types of invitation envelopes.
The announcement envelope has a rectangle flap, but the baronial has a pointed flap.
The largest baronial envelope measures 7.5 by 5.5 inches, but the biggest announcement envelope measures 9.5 by 6 inches.
The baronial also has diagonal seams, while the announcement envelopes have side seams for a more polished look.
Booklet
The booklet envelope ranges in size from 4.75 x 6.5 inches all the way up to 10 x 13 inches.
The design comes with a side beam and a square flap, and it works well with automatic insertion.
It’s mostly used by companies to send their brochures and sales materials through the mail.
Square
Don’t confuse the square envelope with the seemingly square 4.5 x 5.75 envelope.
The square envelope is literally square, and its unusual shape is why some people like to use it to garner attention.
Just keep in mind that you’ll need extra postage to mil this envelope.
It can measure 4.75 inches in all sides, up to 9.5 inches on all sides.
This comes with side seams and a modern square flap.
Remittance
These remittance envelopes are also known as donation envelopes.
These are often used by churches, schools, charities, and other fundraising groups.
Monarch
The monarch envelope is also called the #7¾ envelope, and it’s a type of business envelope.
It measures 3⅞ inches from top to bottom, and 7½ inches from left to right (3.875 x 7.5).
The flap can be on the top along the length of the envelope.
But you may also find versions with a flap opening on the short side.
These are often used for personal or casual business correspondence.
Wallet Flap
The wallet flaps refer to envelopes that are longer than usual.
These can measure 4⅛ by 9½ inches (4.125 x 9.5), up to 6 by 12 inches.
The design often has a deep flap with a wide gummed area for a secure seal.
Banks and investment firms mainly use these to protect some specialized types of documents.
Uses of the 5.75 x 4.5 Envelope:
As you may now realize, different envelopes have different uses.
The envelopes by size can denote a certain level of formality, while also accommodating your materials.
So how do you use a 4.5 x 5.75 envelope? Here are some suggestions, depending on the type you get.
Formal Invitations
These can even work for wedding invitations.
What you need here is to check the overall impression of the card.
The most important factor here is the thickness (weight paper) of the envelope.
It has to be thick and heavy.
It’s hard to take cards seriously when they come in thin envelopes.
Also, thin envelopes are easier to fold, and that ruins the whole formal effect.
Semi-Formal Cards
You can go with these A2 envelopes for cards that aren’t too formal at all.
But when paired with the right envelope, it gives off a semi-formal vibe.
That works very well with baby showers and other important announcements.
For a less formal vibe, you can go with the brown kraft paper.
The rustic vibe really tones down the formality, but it’s not overly casual.
Fun Greetings
Now you can always use these envelopes for really fun and casual greeting cards.
These can be cards sending get-well messages, birthday greetings, or happy holidays.
When you’re sending handcrafted cards or super-colorful cards, then you may want to go wild with your color selection.
You can even get a variety pack with different colors.
Reply Envelopes
When you’re sending larger A-style envelopes, you can insert this A2 envelope inside.
Since this is the smallest A-style envelope, it’ll fit in those larger envelopes.
This works very nicely in RSVP situations, so that your loved ones can reply tight away to your invitations.
You can even pre-address these envelopes yourself, especially if you pick envelopes that work with your printer.
Promo Materials
You can send customers various posters and brochures in your direct mailings.
You’re not even limited to smaller paper sizes.
Instead of folding the 8.5×11 paper in three portions, fold it into quarters and it will fit into the A2 envelope nicely.
These can also fit in 4×5 photos without any trouble.
If you want, you can even use the brown kraft envelope to give off an air of eco-friendliness.
Part of these envelopes is made with recycled paper.
Our TOP 5 4.5 x 5.75 Envelopes
If you’re unsure of what 4.5 x 5.75 envelope to get, just pick a 4, 4.5 x 5.75 envelope from these top contenders:
1. Azaza 100 Pack, Size A2, White Paper Envelopes
“White Color Eco-Friendly Envelopes”
Our Rating: 5
As we’ve mentioned before, looking for a 5.75 x 4.5 envelope may not be ideal.
What you probably need is the A2 standard size, which actually measures 4.375 x 5.75 inches.
These are the envelopes you need when you use the A2 standard size for your greeting card that measure 4 by 5 inches.
The snugger fit minimizes the chances of accidental folding of the envelope along the way.
You also have the modern square flap here, which seems classier than the businesslikecommercial flap on other envelopes.
Eco-Friendly White
Some people are torn between picking the classic white color for their formal announcements and the environmentally responsible brown kraft paper.
This gives you the best of both worlds.
You get the white color which is more formal, but this 5.75 x 4.5 envelope is actually made with eco-friendly materials.
Off-White Color
Thiswhite wove paper actually isn’t plain white.
It’s more of an off-white color.
This still looks white when it’s side by side a colored envelope.
But if it’s among other white wove envelopes, the off-white stands out.
This is actually part of the Azaza company policy, which is to provide beautiful and also useful items with eco-friendly materials at a reasonable price.
Heavy Paper
This gives off an undoubtedly formal impression, due not only to the color but also to the thickness of the paper.
It uses 120 gsm paper, also known as 32-pound bond paper or 80-pound text paper.
Because of this thickness, you can be reasonably sure the envelope won’t just tear while in transit.
It also offers privacy, as it’s opaque to keep anyone from peering through.
Even if you put in a deep blue card inside, you won’t be able to tell the color of the card from the outside.
Quick and Easy Self Seal
The flap here is substantial, and when folded reaches almost up to the center of the envelope for a classier look.
Sealing this is easy, as you just have to peel the cover from the adhesive strip.
Press firmly, and you get a strong seal.
2. Wan 100 Pack, Size A2, Thick Brown Kraft Paper Envelopes
“Very Thick and Environmentally Friendly”
Our Rating: 5
We again went with 100 envelopes in a pack, which is a number that should match the number of invitations you send out.
If it’s too many, you can use them for other occasions as well.
Uses
For some people, brown kraft paper offers a somewhat less formal and more rustic vibe.
That may be the kind of vibe you’re looking for when you send your announcements or invitations using this 4.5 x 5.75 envelope.
You can also use these to send photos and greeting cards.
But an increasing number of people these days think of brown kraft as a classy alternative to white envelopes.
After all, it also quickly denotes eco-friendliness, as brown kraft paper is known to be.
These also work as great mini envelopes for promotional items and samples of small office products, along with brochures and other sales materials.
Heavyweight
One of the ways that distinguish this envelope is the fact that it’s very heavy – this uses 148 gsm paper, and that’s really thick and heavy.
It’s far from being a translucent envelope.
In comparison, regular office letter-sized paper is 80 gsm.
This is also defined as 100-pound text paper.
The thickness of this 5.75 x 4.5 envelope gives the gravitas and formality you want for your announcements.
That’ll help in case you’re worried that the brown color makes it seem more informal.
Tough
The thickness of the paper also adds a tough layer of protection for your announcements,
You won’t have to worry about your invitations and greeting cards getting damaged along the way to the recipient.
This is no ordinary envelope that will tear easily.
Seal
The seal here is self-sealing, with a protective cover for the adhesive strip.
Just peel off the cover when you’re ready to seal it, and then press the flap on the envelope firmly.
The only issue is that in some packs, one (or two) of the envelopes are missing an adhesive strip.
It’s an annoying issue, but a glue stick solves the problem.
3. Quality Park Invitation Envelopes, #5.5, White, 4.375 x 5.75
“Ideal for Handmade DIY Invitations”
Our Rating: 4.5
This 4.5 x 5.75 envelope is also an A2 envelope, with a white color for a touch of elegance.
It’s ideal for social greeting cards and announcements.
The seams are all on the edges, so the front and back sides are smooth and neat.
It’s more formal than casual, but it’s not too formal and stiff.
This also works very well for promotional materials for your company.
Measurements
It can fit in a regular letter-sized sheet (8.5 x 11) when it’s folded in quarters.
The size of the resulting folded paper will then be just 4.25 x 5.5 inches.
Paper Quality
The paper here is premium white wove stock with 24-pound thickness.
This is more than strong enough for the mail delivery system, and can protect your announcements and photos inside.
Even if the box it comes in is damaged (which can sometimes happen), the envelopes inside aren’t really damaged.
It does seem a bit thin for some uses, such as if you’re putting in a colorfulgreeting card.
The good news here is that this 5.75 x 4.5 envelope works nicely with printers, whether you’re using an inkjet or a laser printer.
Using a printer is a lot more convenient when you’re addressing 100 envelopes.
Sealing the Flap
This also comes with gummed enclosure, which you can moisten to activate.
This type of enclosure is actually recommended for machine insertion.
If you’re wetting the adhesive manually, press it firmly for a minute to make sure it stays glued.
The adhesive also doesn’t go through the entire length of the flap, which makes this easier for the recipient to open.
4. Aimoh 100 White A2 Invitation Envelopes (36100)
“Perfect for Thank-You Cards”
Our Rating: 4.5
This is more expensive than the other 5.75 x 4.5 envelope brands on this list so far.
But with the benefits you get, you probably won’t mind paying just a few dollars more per pack.
Flap Design
Let’s focus right away on what makes these envelopes different.
That’s the flap, which doesn’t come with the normal square flap design, but instead comes with an executive V-shaped flap.
This makes it more of a baronial-style envelope that is a tad more informal, but that’s okay for certain types of uses.
If you’re into colorful and casual greeting cards, then this will work nicely.
When the recipient opens the flap, the V-cut design on the envelope shows part of the greeting card.
It acts like a preview, as it hints of the card to come out.
Not Too Formal
The paper used here is actually somewhat thin, compared to some of the more formal and heavier envelopes.
Again, that actually works for some uses.
The recipient can get a hint of the greeting card they’re getting right away.
However, this actually works very nicely with envelope liners.
The liners provide privacy, but with the right design the lined envelopes also complement your invitations and cards.
In fact, with the right design you can even increase the formality of the envelope.
Gummed Adhesive Seal
This comes with a gummed adhesive, which need moisture to activate.
This can work with bulk mailing machines.
It even works nicely with most inkjet and laser printers.
Depending on the design you use for the envelope, you can end up with an envelope that looks a bit more formal.
5. A2 Invitation Envelopes
“Great for All Invitations”
Our Rating: 4.5
This is available in a pack of 1,000 envelopes.
That works out nicely when you’re sending out invitations for a huge bash.
But it’s also great if you’re just stocking up, since you may want to keep using this particular 4.5 x 5.75 envelope.
Bright White
Now this is really bright white, and some may even call this colorsolar white.
It offers a formal vibe that works well enough for wedding invitations.
But you can also use this envelope for more casual party invitations or even for just holiday greeting cards.
Packaging
This set comes in 4 boxes, with 250 envelopes per box.
The boxes are all labeled, and they work well enough as storage for the envelopes.
The really good news here is that the price per envelope drops down drastically when you buy 1,000 envelopes at once.
Considering that it has 1000 envelopes, its price per envelopeis just ⅓ that of the prices of the other brands.
Square Flap
This comes with the regular square flap, and the flap measures 2-5/16 inches.
It’s very easy to slip in your cards, photos, and letters through this flap.
The flap also comes with the regular gummed flap that requires moisture to activate.
Formal Looking White
The white here does look formal, with the 24-pound paper offering the right sort of weight and thickness for the envelope.
The square flap also gives off a more formal vibe, compared to the regular v-folds.
It also doesn’t tear off easily.
The weight of the card, however, tempers the formality.
The thickness makes it less formal, so it works for casual cards as well.
Use this for your handmade cards, and the overall effect makes people think that you spent extra effort on sending your greetings to your loved ones.
4.5 x 5.75 Envelope: Conclusion
Now that you know about various envelope sizes, you may find the right 5.75 x 4.5 envelope that fits your needs.
With the right pack of these envelopes, you can then have an envelope that works for a wide variety of uses.
Use the right 4.5 x 5.75 envelope and you have something that works with greeting cards, formal invites, photos, promo materials, and even some sales items!
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