Free design proof on every custom order: no templates, no stock SKUs
The #10 envelope, 4.125" x 9.5", is the standard size for U.S. business correspondence, sized to hold an 8.5" x 11" letter folded in thirds without excess bulk. It's the envelope most offices reach for by default for invoices, statements, letters and general mailings. Available with or without a window for a visible mailing address, and in a range of stocks from everyday white wove to heavier textured papers for higher-visibility mail.
An estimator will reply within one business day.
The #10 is the envelope size most people picture when they think of ordinary business mail, and for good reason: at 4.125" x 9.5", it's built specifically to hold a standard 8.5" x 11" sheet folded into thirds, the most common way a business letter gets prepared for mailing. That close match between paper and envelope size is what makes it the default choice across offices, banks, law firms and any business sending routine correspondence.
Two construction details matter most when ordering. The first is whether the envelope has a window, an open or film-covered cutout that lets the recipient's address printed on the letter itself show through, which saves a separate step of printing or handwriting the address directly on the envelope. Window envelopes are especially common for invoices and statements, where the return address, account details and mailing address are all generated together on the enclosed document. The second is closure: standard gummed flaps need to be moistened, while self-seal envelopes use a peel-and-stick strip that speeds up high-volume mailings considerably.
Stock choice affects both cost and how the envelope reads on arrival. A standard white wove paper in the 24 lb range covers most everyday business use, while a heavier stock or a subtle texture can make an envelope feel more substantial for correspondence meant to stand out, such as a welcome packet or a formal notice. Security tint, a fine pattern printed on the inside of the envelope, is worth considering for anything containing sensitive information like account numbers or personal data, since it prevents the contents from being read through the paper when held up to light.
The #10 is frequently ordered alongside a smaller #9 envelope sized to nest inside it as a return envelope, a common pairing for invoices, donation requests and any mailing that expects a reply. For pieces too bulky to fold or content that needs to arrive flat and uncreased, a larger flat envelope is generally the better fit instead.
Envelope weight is doing two jobs: it decides how the piece feels when it arrives, and it decides whether the contents show through. A 24lb wove is the everyday business standard and hides a folded letter adequately. Step up to 28lb or 32lb where the contents are thicker, where a check or a dark-printed insert would otherwise ghost through, or where the envelope itself is meant to signal that something considered is inside.
Why can I see the contents through my envelopes? The stock is too light for what is inside. Either move up a weight or add a printed security tint to the interior.
The constraint that surprises people is that you cannot print wherever you like. Postal systems reserve areas of the face for the address block, the postmark and machine-readable barcodes, and artwork intruding on them can slow a mailing down or get it rejected. Everything else is available (the flap, the reverse, and the areas of the face outside those zones) which is why so much envelope design lives on the back.
Can I print across the whole front? No. The address block, postmark area and barcode zone have to stay clear. We will show those on your proof.
How the envelope is folded and glued determines what it is good at. A side-seam envelope has glue lines up both edges and lies flat and rigid, which is what business correspondence and machine insertion need. A diagonal-seam envelope folds from a single diamond blank with the seams meeting in the middle. Traditionally the more formal construction, and the one used for invitations and announcements.
Does the seam matter? For machine inserting, yes. Side seam feeds reliably. For a hand-addressed invitation, diagonal seam simply looks right.
Three closures, chosen against volume and by hand or by machine. Gummed flaps need moisture and are the cheapest. Fine for a machine, tedious by hand in quantity. Peel-and-seal has a release strip over a pressure adhesive and is far faster for hand assembly. Latex self-seal bonds only to itself, so envelopes can be stacked without sticking and closed with a press.
Which for a hand-stuffed mailing? Peel and seal, without hesitation. The extra cost per envelope is recovered in the first hundred you do not have to lick.
At 4.125″ × 9.5″ this is the default size for United States business correspondence, dimensioned so an 8.5″ × 11″ letter folded in thirds slides in without bulking or binding. Because it is the standard, it is also the size every inserting machine, postal rate and window position is designed around, which is exactly why deviating from it costs more than the paper saving is worth.
Where does the window sit? In a standard position matched to common letter templates. If your letterhead places the address differently, send it and we will check the alignment before printing.
Ask for samples before committing. Show-through and how a stock takes a fold are both impossible to judge on screen.
A return address and a logo, printed directly. It is the cheapest way to make mail look like it came from an organization rather than from a printer, and on a business envelope it is often all that is needed.
Photographic and full-bleed artwork. Worth noting that full-bleed coverage is only truly achievable on custom envelopes printed flat before converting. On a pre-made envelope the seams and flap edges limit how far ink can reach.
Metallic foil pressed into the stock, most often on the flap or as a monogram. On a textured or laid envelope the combination of foil against the ribbed surface is the traditional formal treatment.
A die-cut aperture backed with a clear film so an address prints once, on the letter, and shows through. It removes a whole addressing step from a mailing, which is why it dominates invoicing and statements.
Same family, genuinely different jobs. Your current selection is highlighted.
| Envelope | From | Format | Order it when |
|---|---|---|---|
| #10 Envelopes | $220 | 4.125″ × 9.5″, letter in thirds | Standard US business correspondence |
| #9 Envelopes | $220 | 3.875″ × 8.875″, nests in a #10 | A reply envelope goes in the mailing |
| 9 x 12 Envelopes | $240 | Holds letter size unfolded | The contents must not be folded |
| DL Envelopes | $190 | 110mm × 220mm, A4 in thirds | Letters and invoices on A4 |
| C6 Envelopes | $180 | 114mm × 162mm, A4 in thirds | Cards and shorter ISO correspondence |
| Custom Envelopes | $190 | Printed flat, converted to size | No stock size fits, or you want full bleed |
In a standard position matched to common letter templates. If your letterhead places the address block differently (and many designed letterheads do) send the letter and we will check the alignment before printing rather than after.
Not on a pre-made #10. Ink cannot run cleanly over the glued seams and the flap fold, so there is a small unprinted margin. If you need genuine full bleed, the envelope has to be printed flat and converted, which makes it a custom order.
A few folded sheets comfortably. Past that the envelope bulks, the flap strains and postal rates often change bracket anyway. At which point a 9 x 12 flat envelope is usually both cheaper to mail and better presented.
Peel and seal if the mailing is stuffed by hand, gummed if it goes through an inserting machine or if cost per envelope is the deciding factor. For anything over a hundred pieces by hand, peel and seal pays for itself.
Pricing for #10 envelopes starts at $220 and moves with quantity, size, material and finish rather than sitting on a fixed list. Setup is shared across the run, so the per-unit price drops steeply as the quantity rises: the gap between a few hundred and a few thousand is usually the significant one. Send the size, quantity and what it has to do and you get a firm figure back, not a range.
There is a practical minimum rather than a hard one. Every run carries artwork checks, a proof and a press setup, so a very small quantity of #10 envelopes prices poorly per unit even though we will still make it. If you are ordering a small batch, ask for pricing at two or three quantities at once: the curve usually shows that a modest increase costs very little more in total.
The clock starts when you approve the proof, not when the order is placed, which is the part most people are surprised by. You get a proof first: a digital proof showing the artwork with the clear zones and, where relevant, the window position marked. Nothing prints until you approve it. On a custom conversion the proof also shows the flat blank before folding. Turnaround after approval depends on the finish: anything laminated, foiled or die-cut adds a stage that cannot be compressed without causing problems later. Tell us the date you actually need them and we will work backwards from it rather than quoting a generic lead time.
Print-ready artwork with bleed and a safe margin, supplied as a PDF, AI or EPS. Photographic elements should be supplied at the resolution the finished size needs, not the resolution that looks sharp on screen. If your file is not print-ready, say so when you order. We would rather fix it before the proof than after the run.
Yes. #10 commercial, letter in thirds is the standard build, and the dimensions around it are yours to set. A size that sits efficiently on the press sheet often costs no more than a standard one, while an awkward proportion that wastes half the sheet does. Ask before you commit and we will tell you whether a small change to the dimensions saves a disproportionate amount.
In most cases they are the same product under a different name: the trade uses several terms for it depending on the region and the supplier. What actually defines this one is the build: 4.125″ × 9.5″, letter in thirds. Order it when standard US business correspondence. If you have seen it called #10 envelopes printing elsewhere, describe what it has to do rather than which name you found, and we will match the specification.
Yes. We provide free samples, and on #10 envelopes it is worth asking for one, because the difference between white wove and white wove, heavy is obvious in the hand and invisible on a screen. Most orders run on white wove, but ask for whichever you are weighing up. You also get a free design proof before anything goes to press, so nothing is printed that you have not seen.
The usual choices are one or two color, full color, foil stamping. Finish is not decoration on this product so much as a decision about how long it survives and how it reads in the hand, so it is worth choosing against the job rather than the budget. Tell us where the finished piece ends up and we will say which finish is doing real work and which is only adding cost.
Yes, and that is what almost every order here is. Nothing in this catalogue is a stock item: #10 envelopes are manufactured to the specification you give us, with your artwork on them. Send your logo as vector artwork where you have it, since that scales to any size without softening. If all you have is a low-resolution file, tell us and we will say what it needs before it reaches the press.
Yes, and a repeat run is simpler than the first one. We keep your approved specification on file, so a reorder skips the setup decisions and goes straight to production. If nothing about the artwork or the specification has changed, there is nothing to re-approve. Tell us the previous order and we will match it rather than starting the specification again.
Yes. Regalo Print has been producing custom commercial print for businesses across the USA and Canada since 2008, and every order ships tracked. The tracking number reaches you the day the job leaves, not the day it arrives. If you are working to a fixed date, say so when you order so the production schedule is built around the delivery date rather than the other way round.
