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Proposed Rule

Letter-Size Booklets and Folded Self-Mailers

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Information about this document as published in the Federal Register.

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Postal Service.


Advance notice of proposed rulemaking.


The Postal Service is developing new mailing standards for folded self-mailers, booklets, and folded booklets mailed at automation and machinable letter prices. This notice provides advance information about the mail preparation changes to help mailers plan for future mailings.


We must receive your comments on or before April 14, 2008.


Mail or deliver written comments to the Manager, Mailing Standards, U.S. Postal Service, 475 L'Enfant Plaza, SW., Room 3436, Washington, DC 20260-3436. You may inspect and photocopy all written comments at USPS Headquarters Library, 475 L'Enfant Plaza, SW., 11th Floor N, Washington, DC between 9 a.m. and 4 p.m., Monday through Friday.

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Barry Walsh, 202-268-7595, or Bill Chatfield, 202-268-7278.

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Due to the price increases associated with mailing flat-size catalogs last year, letter-size catalogs have become more popular. These types of letter-size booklets and folded self-mailers are often called “slim jims.” Unfortunately, many slim jims will jam letter automation equipment or become significantly damaged during processing. To avoid these problems, slim jims often are run on flat-sorting equipment, where they process without significant problems, but at significantly greater cost. To rectify this situation, the Postal Service is developing new automation mail preparation standards for letter-size booklets and folded self-mailers that more accurately characterize which pieces can be run on our primary letter-sorting equipment.

In addition, we have observed an increase in untabbed booklets that are entered at machinable (nonautomation) prices. Many of these booklets cannot run on our primary letter-sorting equipment, even if tabbed. Our new mail preparation standards will better align the machinable and automation requirements and outline new tabbing requirements for efficient letter mail processing.

Mailpiece Testing

Letters processed on our primary letter-sorting equipment travel around turns and through gates at the rate of 10 letters per second. In this environment, the physical behavior of booklets and folded self-mailers differs significantly from enveloped pieces due to a number of physical characteristics. We consulted widely with mailers, printers, manufacturers, and USPS field processing operations to determine the physical characteristics that were most likely to be both important in processing and compatible with industry practices. The characteristics chosen for testing were: Size, thickness, cover stock, tab style, tab strength, tab location, and binding (either stapled on a single fold; stapled and folded twice; or folded twice and unstapled—a folded self-mailer).

The USPS Engineering department designed testing in two phases, with the first phase intended to determine the characteristics of a mailpiece that are most important for efficient processing. In this first phase, test pieces were intermixed with enveloped letters to replicate normal postal processing. Damaged pieces were removed between runs, and we compiled statistics on jams and damage. A second phase will determine and verify the specific limits on each characteristic for automation-compatible booklets and folded self-mailers. In this notice, we report the results of the first phase to provide mailers with the earliest possible test results and opportunity to comment.

Preliminary Data

The first phase of testing revealed that the most important characteristics by far are thickness and tab integrity, and that each of these characteristics is independently important. The next most significant characteristic is the cover stock.


We tested two mailpiece thicknesses: 1/16 inch and 1/8 inch. As long as the tabs remained in place and did not break, the 1/16-inch-thick pieces ran with jam and damage rates somewhat higher than the rates anticipated for similar enveloped letters. The 1/8-inch-thick pieces sustained unacceptable rates of jams and damage throughout the range of all characteristics tested.


We tested 1-inch paper tabs, both perforated and nonperforated, with three paper strengths—28/30, 42/45, and 56/60 (inline/cross directions). The perforated tabs were 2.5/2.5/3.9 (2.5 mm perforation/alternating with 2.5 mm of uncut material/with a perforation starting 3.9 mm from each edge). We also tested 1-inch plastic tabs with two levels of perforation—2/1/1 and 2.5/3/3. The weaker variety (2/1/1) of plastic tab broke readily in processing, yielding unacceptable levels of jams and damage. Start Printed Page 13813All of the other tabs that we tested performed reasonably well when fed with tabs on the top, or on the left and the right edges of the mailpiece. When fed with tabs on the bottom, performance was unacceptable.

Cover Stock

We tested 20- and 28-pound bond cover stock. The heavier cover stock performed better.

Other Characteristics Tested

Variations of size (5″ x 83/8″ and 6″ x 107/8″), tab location (top and ends as specified in the Domestic Mail Manual, section 201.3.0), and binding did not have a significant effect on the test results for the 1/16-inch-thick mailpieces.

Additional Mailpiece Characteristics

Other characteristics are known to be important. These characteristics include surface friction, static attraction, and tear strength on the cover; tab adhesives; tab application; and compatibility with current letter trays (slim jims are more sensitive to damage than regular enveloped letters). We will provide new standards for these characteristics in a future proposed rule.

Machinable Letters

Once we complete the new standards for booklets and folded self-mailers, we plan to extend those standards to all machinable letters. Booklets are mailable at automation prices when barcoded and tabbed or sealed. However, booklets with the spine on the bottom edge but without tabs are currently allowed as machinable letters when they are not barcoded. In the future, we plan to allow nonbarcoded booklets and folded self-mailers to be mailed as machinable letters only if they meet all of the mail preparation requirements for automation letters. This change will ensure efficient mail processing for all letter-size booklets and folded self-mailers.

Comments and Suggestions

We encourage mailers to send their comments and suggestions on the information provided in this notice. We are especially asking mailers to suggest any new or alternative booklet construction techniques that will improve machine performance on 1/8-inch and 1/16-inch booklets. Suggestions on tab adhesive are also appreciated.

We will continue to consult with the mailing industry to develop and test the mailing standards. For example, we intend to investigate to what extent pieces between 1/16-inch and 1/8-inch-thick will process acceptably, whether there is a (not-yet-tested) variety of closure or configuration that will make 1/8-inch-thick pieces acceptable, and the impact of lightweight pages or having the spine on the short edge (i.e., the leading edge).

In addition, since it may be difficult for mailers to identify tabs with appropriate materials, size, perforations, and adhesives, we will investigate a means to certify and mark acceptable tabs. Perforation makes it difficult to inspect tab strength. Perforated plastic tabs are especially problematic, as they raise additional issues with adhesive bonding and leakage. We would appreciate comments on the impact of prohibiting perforated tabs until certification procedures are developed.

Next Steps

Once our testing is completed and the results are validated, we will publish a proposed rule in the Federal Register, with a request for comments on the revised mailing standards. The revised standards will not change the preparation criteria for enveloped letters. Fully enveloped pieces up to 1/4-inch thick that meet automation standards will continue to be accepted at automation prices.

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Authority: 5 U.S.C. 552(a); 39 U.S.C. 101, 401, 403, 404, 414, 416, 3001-3011, 3201-3219, 3403-3406, 3626, 3632, 3633, 5001.

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Neva R. Watson,

Attorney, Legislative.

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[FR Doc. E8-5094 Filed 3-13-08; 8:45 am]