Perforated mystery

December 29, 2012 12:07 PM

What's that perforated part on the back of an envelope for?

Often on the back of an envelope with a horizontal flap, there is a detachable perforated part separate from the sticky bit. What's it for? Should I remove it before sending?

It kind of looks like this deep flap envelope, but the detachable part is far, far smaller.

posted by devnull to grab bag (9 answers total)

It's probably to make it easier for the recipient to open.
posted by TG_Plackenfatz at 12:32 PM on December 29, 2012

From the same page you linked: "Extended closing flap has a perforation at the edge of the gummed area to use the detachable part of the flap as a reply coupon."
posted by matlock expressway at 12:40 PM on December 29, 2012

as a reply coupon

The flap I am referring to is too small for this.
posted by devnull at 12:43 PM on December 29, 2012

Might it be a secure mail envelope?

The envelope of the present invention is prepared from a single blank of material to include easy opening means and security features for tamper evident delivery of credit cards, debit cards and other sensitive material. The envelope structure includes a bangtail flap foldably attached to the rear panel of the envelope and folded inside the envelope, a pair of perforated lines located on each side of the rear panel for providing access to the inside bangtail flap, and a separate opening means for the closure flap.

posted by thatdawnperson at 1:15 PM on December 29, 2012

This is on a birthday card though. Or a Christmas card..
posted by devnull at 2:52 PM on December 29, 2012

I've never seen that on an envelope someone would send a card in, and now I'm curious. Could you take a photo of it?
posted by The corpse in the library at 3:18 PM on December 29, 2012

hmmm...could it be for writing the price of the envelope/card on? a leftover from the days before barcode scanners?...i have seen similar on gift items, boxes of chocolates, usually, where the label is a sticker, but the bottom flap with the price is ungummed and preforated so you can take it off easily.
posted by sexyrobot at 3:49 PM on December 29, 2012

Generally this is used for a "two-way mailer" variously known as a "remittance envelope". [see also] The general idea is that the perforated part has the customer mailing address and postage and covers up the reply address, saving the inclusion of a completely separate reply envelope.

The one most people are familiar with now is Netflix shippers, but a lot of utility bills used to come in this form, sometimes highly customized due to the large volume. One common type is the bangtail or coupon envelope, but those don't sound like your description.

It's pretty uncommon to see these as blanks, but I suppose an invitation, for instance, where an RSVP is expected could be one low-volume type of application. But mostly these are used for remittances of one kind or another.
posted by dhartung at 5:33 PM on December 29, 2012

Unfortunately I didn't find an enveloper to take a photo of, but I do know it's not a coupon envelope or bangtail enveloper. Neither is it a two way mailer: the detachable flap is the same small size as the sealable flap.
posted by devnull at 7:45 AM on January 22