Technical Specifications

Envelope Specifications

In response to the Royal Mail tightening up their checks of machinable mail against the specification, we have revised our envelope specification to meet Royal Mail guidelines more explicitly. This is to help avoid costly mail reversions.

When supplying outer envelopes, or artwork for outer envelopes for us to produce for machinable mail, please follow the attached specification for flap shape and glue areas. Where outer envelopes are received outside of this specification, we will ask you to confirm if you would like us to proceed down the machinable mail route, and cannot be held responsible for any reversions as a result of insufficient sealing.

Envelope Specification
Envelope specEnvelope Style: Wallet
Minimum Envelope Size: C6
Maximum Envelope Size: C4
Other Envelopes: Any size that falls between C6 and C4
Side to Side Clearance: 15mm Minimum for ALL ENVELOPE SIZES
Paper Stock: Minimum 80gsm, Maximum 115gsm
Envelope Flap Depth: Minimum 40mm
Preferred Envelope Design: Straight Flap (see below)

Royal Mail Sealing Specification

Due to the changes in the Royal Mail application of the specification for sealing envelopes we have reviewed all of our specifications and our findings would indicate that envelopes with a straight flap (see above diagram) are more reliably sealed and less prone to the Royal Mail enforcing a reversion based on the envelope flap not being sealed all the way across.

GI will accept other style envelopes but will not be held liable for any reversion costs if the envelope is out of our specification.