The envelope is the first thing anyone sees

Invitations get designed carefully and posted in whatever envelope the shop had. That is a shame, because the envelope is the part your guest handles first, and it is the part that decides whether the card arrives flat or with a corner bent through it.

Getting it right is mostly a question of matching three things: the size to the card, the paper to the postal journey, and the addressing to the amount of time you actually have. None of these is expensive to fix at the ordering stage, and all of them are annoying to fix afterwards.

Sizes that actually fit

An envelope needs to be larger than its contents in both directions, not just in one. The usual allowance is about 5mm on each side, which lets the card slide in without a fight and without rattling around. Card sizes and envelope sizes come from different naming systems, so it is worth checking the pairing rather than trusting a name.

• C6 (114 x 162mm) takes an A6 card, the standard small invitation
• C5 (162 x 229mm) takes an A5 card, or an A4 sheet folded once
• DL (110 x 220mm) takes a third-of-A4 slip, common for tickets and vouchers
• 5 x 7 inch (133 x 184mm) is the classic wedding invitation size, sold under that name rather than a C number
• Square envelopes pair with square cards and look excellent, with one catch below

The catch with square: many postal services charge a surcharge for square envelopes because they do not run through automated sorting machinery the same way. On a run of 20 that is nothing. On 200 it is worth knowing before you commit to the shape.

If your invitation includes inserts - an RSVP card, a map, a menu slip - measure the stack, not the main card. A set that totals 2mm thick sits fine in a standard envelope. A set with a thick backing board and a ribbon does not, and it will burst the seam somewhere between the postbox and the recipient.

Printing on the envelope itself

Return address on the flap

The cheapest useful upgrade. A printed return address on the back flap costs little, looks finished, and gets undelivered invitations back to you rather than lost. For a wedding it also gives guests somewhere to send a reply if the RSVP card goes missing.

Printed liners

A liner is a sheet printed on the inside of the flap, usually in a pattern or a colour that picks up the invitation design. It is the detail people remember from opening the envelope. Liners can be printed and fitted as part of the order, or supplied as pre-cut sheets for you to glue in yourself if you would rather spend an evening on it than the money.

Full colour and dark envelopes

Envelopes can be printed edge to edge, though heavy coverage on a folded envelope will show slight cracking along the fold on some stocks. Dark envelopes look striking and create one practical problem: ordinary black ink disappears on them. Addressing on a dark envelope needs white ink, a metallic, or a printed label in a lighter colour.

Getting the addresses on

There are three routes, and the right one depends on how many you have and how much time is left.

Printed directly. Addresses are merged from your spreadsheet and printed straight onto each envelope. It is fast, consistent, and by far the least work for anything above about thirty. The spreadsheet is the whole job here: one row per guest, one column per line of the address, spelling checked before it goes anywhere near a press.

Printed labels. Practical and quick, though a label always reads as a label. Clear labels on a pale envelope come closest to looking printed on. On a textured or dark envelope, labels are usually the honest choice rather than fighting with ink.

By hand. Calligraphy or your own handwriting suits a small, personal list. Allow far more time than you think: forty envelopes written carefully is an evening, and the last ten always look different from the first ten. Write a few spares, because a slip of the pen on the final envelope of a numbered set is a real annoyance.

Whichever route you take, order about ten percent more envelopes than you have guests. Addresses get corrected, envelopes get scuffed in a bag, and someone always gets added to the list late.

Paper, weight and the postbox

An envelope around 100 to 120gsm handles ordinary post without showing the card through it. Lighter than that and a dark invitation shows as a shadow through the paper. Heavier stocks feel substantial and are worth it for a small run, but check the total weight of the finished item against your postage band before you order 150 of them, because crossing into the next band doubles a cost you had not budgeted.

Peel-and-seal flaps are quicker than gummed ones and worth the small extra when you have a hundred to close in one sitting. If your envelopes are going into a printer for addressing, mention that when ordering, since some self-seal designs do not feed well and are better addressed first.

When to order and when to post

Invitation timelines run backwards from the event, and the envelope is usually the step nobody allowed for. A useful sequence for a wedding is to have invitations in guests' hands about three months ahead, which means posting them four months ahead if any are going overseas.

Working back from the posting date: allow a week for addressing if you are writing by hand, two days if we are printing them, and a couple of days on top for stuffing and sealing. Stuffing 150 envelopes with three inserts each takes longer than anyone predicts, and it is a job that goes much faster with two people and a table than one person on a sofa.

Before that comes the print run itself, and before that the proof. If a name is spelled wrong on a proof, the correction and the new proof add a day or two. So a comfortable plan puts the artwork with us about three weeks before the posting date, and a tight one about ten days.

One more scheduling detail catches people. Take a fully stuffed, sealed sample to the post office and have it weighed before you buy stamps for the whole run. Postage is priced by weight and by thickness, and a set that crosses a threshold because of one extra insert changes the cost of every envelope you are about to send.

Ordering envelopes with your invitations

Ordering both together is simpler than sourcing them separately, mainly because we can check the fit before anything is printed rather than after. Send the invitation size and the number of inserts, and we will confirm the envelope size that suits it.

• Envelope size, quantity and colour, with the ten percent spare included
• What you want printed: return address, liner, full design, or plain
• Your guest list as a clean spreadsheet, if we are printing the addresses
• Whether the set has to be posted by a particular date, so we can work back from it

We print invitations and their envelopes on the same run wherever the stocks allow, which keeps the colours matched between the two. The custom invitation printing page covers the cards themselves, and on-the-day wedding stationery handles what happens once guests arrive. For a coordinated set beyond the invitation, printing a matching gift set uses the same approach.

Not sure what fits what? Send us the dimensions of your card and we will tell you the envelope, or ask us for a sample envelope before you order the full quantity. It is easier than measuring twice.