Postage for Rigid Invitations
An invitation that does not bend easily is nonmachinable. In a letter-size envelope that adds $0.49. In a large envelope it is worse: a rigid flat is charged as a package.
Your answer
Nonmachinable letter
+$0.49 surchargeLetter postage plus the nonmachinable surcharge, because it has to be sorted by hand.
- Postage per piece
- $1.60
- 100 invitations
- $160.00
Stamps for each one
2 × Forever (1 oz letter)
That pays $0.04 more than needed. For exact postage, ask the post office counter to make up $1.60.
Why
- An envelope that does not bend easily is too rigid for the sorting machines. USPS rule
Rates last verified on
100 invitations: $160.00 in postage ($1.60 each, nonmachinable letter)
What counts as rigid
Letters travel around rollers and curved belts. The USPS standard is that a letter must bend easily around a turn 11 in across. Paper and ordinary card stock do. These usually do not:
- Acrylic, plexiglass and mirror invitations
- Wood veneer, cork and metal cards
- Cards mounted on chipboard or museum board
- Invitations in a hard folio or with a stiff backer added "to keep them flat"
A home test
Take one sealed invitation and curve it gently around something about 11 in across, like a large mixing bowl or a stock pot. If it follows the curve without force and springs back, it is flexible. If you have to push, or you worry it will crease or crack, treat it as rigid.
This is a judgment call, and it is the clerk's judgment that counts. When in doubt, take one to the counter.
Letter size: surcharge only
A rigid piece that is letter size and 3.5 oz or less is a nonmachinable letter. It pays letter postage plus $0.49: $1.31 at 1 oz, $1.60 at 2 oz, $1.89 at 3 oz. Acrylic is heavy, so check the weight; the heavy invitation page covers the steps.
Large envelope size: a package
Large envelopes must be flexible. One that is rigid stops being a large envelope and is charged at package prices, which this site does not calculate. That happens when a rigid invitation is over 6 1/8 in high or over 1/4 in thick. A rigid letter-size piece over 3.5 oz also pays large envelope prices, so this site treats it as a package too; confirm that one at the counter.
A 1/8 in acrylic card with a backer and a padded mailer easily passes 1/4 in. If that is your design, price it with the USPS postage calculator and budget for it early.
Do not add a stiffener to a paper invitation
A cardboard insert meant to protect a paper invitation turns a $0.82 letter into a $1.31 one. Card stock invitations survive the mail without help.
Compare the options
| Option | Mail class | Each | For 100 |
|---|---|---|---|
| Flexible card, 2 oz | Standard letter | $1.11 | $111.00 |
| Rigid card, 2 oz | Nonmachinable letter | $1.60 | $160.00 |
| Rigid card, 3.4 oz | Nonmachinable letter | $2.18 | $218.00 |
| Rigid card, 4 oz | Package | Package price | - |
| Rigid card over 1/4 in thick | Package | Package price | - |
Questions and answers
Do acrylic invitations need extra postage?
Yes. Acrylic does not bend, so a letter-size acrylic invitation pays the $0.49 nonmachinable surcharge, and a large or thick one is charged as a package.
How do I know if my invitation is too rigid?
Curve the sealed envelope around something about 11 in across. If it does not bend easily, it is too rigid for the sorting machines.
Can I add cardboard to protect my invitations?
You can, but a stiff insert makes the envelope nonmachinable and adds $0.49 to each one.
Why is my rigid invitation priced as a package?
Because it is over 1/4 in thick, over 6 1/8 in high or over 3.5 oz. At that size it would be a large envelope, and large envelopes must be flexible.