A effective and affordable direct marketing tool is the classic postcard. Immediately visible to recipients, postcards have instant impact for any marketing campaign.


As you prepare your messaging and files for the postcard, consider the amount of content you will need to effectively deliver your message. To receive postcard rates your dimensions must be as follows:

  • Minimum dimensions 3.5” high x 5” wide
  • Maximum dimensions 4.25” high x 6” wide
  • Thickness between 7 pt. and 16 pt.


If your piece is outside these dimensions, don’t be concerned. The USPS will be glad to mail your pieces under letter rates which are identical to postcard rates for marketing mail (traditionally called bulk rate) or if your mailing saturates carrier routes you can opt for Every Door Direct Mail.


Considerations for Letter-size mail include:

  • Minimum thickness 7 pt is smaller than 4.25” high and 6 inches long; or 9pt if larger than 4.25” or 6” long or both
  • Maximum dimensions 6.125” high, 11.5” Long or .25” thick
  • Rectangular with four square corners and parallel opposite sides. Letter-sized card mail pieces may have a corner radius up to .125” thick.
  • Maximum weight 3.5 ounces
  • Aspect ratio (your piece can’t be too “square”)


Other considerations for your postcard include:

  • paper selection – what will mail well
  • address location on postcard
  • readability and simplicity of messaging
  • all eyes can see your messaging, there is no envelope


We recommend confirming the design of your postcard with us or your local post office before mailing.

For more information about Sentinel Innovation’s custom postcard print services, please call us at 516–486–5000 or use the request button below.