Political Direct Mail Part 2: Size Matters

size matter

When it comes to political direct mail...size matters

With regards to mailing for direct mail, we have discussed the weight of paper and the two general measures used, U.S. Basis Weight and GSM. So onto thickness and size. Both of these are characteristics of printing papers that can affect mailing costs and mail-ability.

Flat, single sheet, large self mailers are often used in political direct mail. Again, there are copious guidelines for mailing at bulk rates. Two important elements of the guidelines are thickness and size.


For standard flats, 8.5 x 11 is a common direct mail size; the USPS has a general guideline that requires a minimum thickness of .009 inches or 9pt in U.S. Measures. Thickness does not necessarily correspond with weight.

For example: Uncoated stock is typically bulkier, thicker than coated stock, even if they weigh the same.

Uncoated Cover Stock                    vs.                    Coated Cover Stock

80 lb .0105 inches or 10.5 pt                                  80 lb .008 inches or 8 pt

100 lb .0135 inches or 13.5 pt                                100 lb .010 inches or 10 pt

The thickness of one sheet of paper is measured in caliper by an instrument called a micrometer. It can either be referred to in inches or points – 1 point is equal to 1/1000 inches, sometimes stated in mics or mils, just to complicate things further.


Dimensions do matter to USPS. Once you have the appropriate weight and thickness for your direct mail piece, you will want to make sure that the dimensions are correct for your mode of mail. For example, standard bulk letters have a maximum requirement of 6.125” for height and 11.5” for length (10.5” for length if folded), maximum thickness of .25” and a maximum weight of 3.3 ounces. In addition to this there is a maximum height: length ratio of 2.5.

Suffice it to say there are a lot of considerations and components of your direct mail pieces that can affect price, mail-ability, appearance and feel. Creative folks may have grand ideas about how to make a piece stand out in the mailbox, but it has to be cost effective and able to get through the post office to have an impact.

Be sure to work with your production team and vendors to work within the USPS guidelines for paper and size. Together you can find ways to produce impactful pieces that are both cost effective and deliverable.