Every transactional document mailer I know uses window envelopes to send the outbound mail. Typically all the bills, statements, or other items they print include the delivery name and address and the intelligent mail barcode. These items are placed on the document such that when the pages are folded the information shows through the window of the envelope and the mail gets delivered.

Mailers have been doing it that way for decades. It was a really smart way to go - in 1975.

Today, there is better technology available that opens the door to a different method which has some big advantages in certain circumstances. Printing the delivery address, return address, logos, and promotional messages on the outside of a sealed envelope containing a personalized document is entirely possible today, and a pretty smart way to run a mail operation.

Only One at a Time
Inserting machines have limitations. Each has a top speed, has a set number of insert stations, and can only process paper with certain characteristics. One of the most restrictive features is a limitation on having only one outbound envelope on board at a time. There's just no way around it. If you want to change envelopes, you've got to stop the equipment and set up a new job. That takes time. The productivity of an idle inserting machine is zero. Depending on how many changeovers are required, and how many adjustments are to be made, a shop might attribute a good portion of their unproductive time to the outbound envelopes.

Double-Windows a Little Better
Mailers have tried to overcome the envelope limitation by using double-window varieties. Though they can be frustrating to get lined up, using a top window for the return address may allow a shop to run all day without changing out the envelopes. This addresses the change-over issue and can offer some of the same opportunities as printing on non-window envelopes. But I still like the closed-face approach the best. Ever since I first investigated the idea back in the late 90's I've thought that once the hardware and software was capable enough, a document operations manager should give serious thought to standardizing on non-window envelopes if they were to build a mailing operation from scratch. Those days are here.

Mail piece integrity systems, computer processing speeds, and inkjet printing quality have all reached the point where mail service providers could produce mail pieces of acceptable quality and accuracy without requiring a window in the envelopes. Migrating away from window envelopes presents some interesting opportunities to lower production costs and differentiate a company from their competitors in the mail service provider business. I think it's worth a look.


1. Combining Jobs - Instead of starting and stopping the printers and inserters all day to run small jobs, combine them into larger batches to reduce unproductive idle time.

2. Folder Adjustments - No need to fiddle with the fold plates to deal with window or address block locations that vary from job to job.

3. Nested Folds - Address blocks on the documents creep up the window on accounts with higher page-counts, sometimes leading to deliverability issues. This isn't a problem with closed-face envelopes.

4. Staging - A day's supply of outbound envelopes staged near the inserters is a lot easier to manage in cramped quarters than constantly moving cartons of job-specific envelopes back and forth to the warehouse.

5. Recovered Document Real Estate - Document designers will no longer have to reserve that big open space on page one for the delivery address. They can take better advantage of the entire page. This could even lead to a reduction in page counts (which saves on paper, maintenance clicks, time, and possibly postage).

6. Purchasing/Warehouse/Inventory Savings - Buying large quantities of a plain non-window envelope is likely to be less expensive than ordering small quantities of single-window designs for every job. Time and money is saved by more efficient warehouse space usage, easier record-keeping, and no waste due to obsolescence or expired shelf life.

7. Messaging - Printing on the face of the envelope doesn't have to be limited to just addresses and permits. Promotional messages, important notifications, maps, and paid ads can be imaged at the same time, taking advantage of the addressee's profile information to include the most relevant and compelling content.

8. Smoother Insertion - Glassine for the window is glued to the inside of the envelope. When a corner or edge of the plastic comes loose it blocks the material from being inserted, causing a jam. Fewer obstructions results in higher productivity on the equipment and a reduction in reprints.

As transactional mail volumes decrease, the benefits delivered by equipment designed to process large quantities of mail are reduced. An inserting operation that can return their average job size to pre-recession volumes by combining the shrunken remnants of stand-alone applications can regain some of the productivity their gear was built to deliver. Switching to closed-face envelopes is one way this objective might be accomplished.

Mike Porter is President of Print/Mail Consultants, a firm that helps document operations save money now and prepare for the future. Connect with Mike directly at Or visit and sign up for Practical Stuff - a free newsletter featuring tips and ideas for operational improvements.