Happy new year… Postcard mailing specs for USPS…

Interesting fact I came across while making our homemade new years card. The maximum thickness for the special, cheaper postcard rate is 0.016 inch (maximum size is 4.25in x 6in).

But the nice thick Enhanced Matte posterboard (24”x30” sheet) is 0.047 inches (1.2 millimeters) according to: http://pe.usps.com/text/qsg300/Q201.htm

I also see there are limits on stiffness so probably this material will not qualify for the postcard rate.

Examples of a nonmachinable letter include:

It has an aspect ratio (length divided by height) of less than 1.3 or more than 2.5 (a square envelope has an aspect ratio of 1, making it nonmachinable).
It is more than 4-1/4 inches high or more than 6 inches long and is less than 0.009 inch thick.
It has clasps, strings, buttons, or similar closure devices.
It is too rigid.
It has a delivery address parallel to the shorter side of the mailpiece.
It contains items such as pens, pencils, or keys that create an uneven thickness.
Letters with nonpaper surfaces, other than envelope windows or attachments that are allowed under eligibility standards by class of mail.

via QSG 201 Commercial Letters and Postcards – Physical Standards for Commercial Letters and Postcards.