Quick answer: an EDDM piece has exactly two jobs: pass the clerk (correct size, the five-line indicia and "Local Postal Customer" block on the top half of the address side) and stop the sort over the recycling bin (one strong image, one readable headline, one specific offer with a deadline). Most pieces fail at the second job, not the first. Here is the design playbook we apply to every EDDM job we print.
Last updated: June 2026. Compliance rules from the official USPS EDDM documentation.
Job One: The Layout USPS Requires
Get the postal mechanics wrong and the design never gets seen. The non-negotiables:
- A qualifying size. EDDM only takes flats; 6.5" × 9" is the safe entry size, 4" × 6" and 6" × 9" are rejected. Full rules in the size chapter.
- The print panel on the top half. The five-line EDDM Retail indicia (top right by convention) and the "Local Postal Customer" block, both on the address side's top half, with clear space around them: no busy photography or reversed type behind the panel. Exact formats in the indicia chapter.
- Print specs. CMYK color, 300 DPI images, and 1/8" bleed on all sides with text kept 1/4" inside the trim. Folded pieces fold on the final (bottom) edge.
Designing in-house? Ask us for a sized template with the indicia and address panel pre-built for your exact dimensions; it's free with any EDDM quote, and it removes the entire compliance layer from your designer's plate.
Job Two: The Anatomy of a Piece That Gets Kept
Residents sort mail in seconds, standing over a bin. Your piece earns a second look or it doesn't. The structure that survives:
| Zone | What goes there | The test it must pass |
|---|---|---|
| Front, top third | One headline stating the benefit or offer, readable at arm's length | Understood in one second, from three feet away |
| Front, dominant visual | One strong image: the food, the finished roof, the smiling result. Not a collage. | Would it stop you? |
| Front, bottom strip | Business name, the offer restated, phone | Visible even if the back is never flipped |
| Back, top half | Indicia + address block (required), logo and return address | Clerk-readable, top half, clear space |
| Back, bottom half | The working zone: offer with deadline, 2–3 proof points, map or service area, CTA, tracking code | One obvious next step |
Design rules we hold every piece to: one message per piece (the card sells the call, not the whole catalog), heavy stock (thin paper reads as junk before a word is read), white space is a feature, and two fonts maximum. The bigger formats earn their print cost here: an 8.5" × 11" with one confident image beats a 6.5" × 9" with six crowded ones, and both mail at the same $0.247 postage.
Headlines, Offers, and CTAs That Pull Response
Patterns we see work across thousands of campaigns, by goal:
| Goal | Headline pattern | Offer pattern | CTA |
|---|---|---|---|
| Grand opening | "Now open in [neighborhood]" | First-visit discount with a date window | "Bring this card" |
| Fill slow periods | "[Weekday] special for the neighborhood" | Day-restricted deal | Order/call with code |
| Seasonal service | "Is your [roof/AC/lawn] ready for [season]?" | Free inspection or seasonal tune-up price | "Schedule before [date]" |
| New patients/clients | "Your neighborhood [dentist/vet] is taking new patients" | New-patient exam bundle with deadline | "Call or book online" |
| Name recognition (farming) | "Just sold on [street name]" | Free valuation or market report | QR to the report |
Two universal rules: every offer carries a deadline (an open-ended discount creates no reason to act this week), and every piece carries a tracking handle: a code, a dedicated number, or a QR, decided before the artwork is final. The results chapter explains why that handle is the difference between knowing and guessing.
The Design Mistakes That Kill Response
The short list, expanded in the mistakes chapter: address panel placed lower-right out of letter-mail habit (violates the top-half rule), six fonts and no hierarchy, the offer hidden in body copy, thin stock, and "we exist" pieces with nothing to act on. If your draft has more than one message, cut until one remains.
EDDM Design FAQ
Which side should the indicia go on?
Either side can be the address side, but whichever carries the indicia and "Local Postal Customer" block is it, and the panel must sit on that side's top half. Most clients put the panel on the back and keep the full front for the offer.
What file specs do you need for EDDM printing?
Print-ready PDF, CMYK, 300 DPI images, 1/8" bleed beyond trim, text 1/4" inside trim. Send what you have, though: every Catdi Printing EDDM file gets a free preflight check, and we'll flag anything before it prints.
Do you have EDDM templates?
Yes: sized templates with the indicia and address panel pre-placed for any qualifying dimension, free on request with a quote. We'd rather hand you the compliant canvas than fix a layout after the fact.
Should I design my EDDM piece myself or use your designers?
If you have a designer, our template plus this page is everything they need. If you don't, our team designs EDDM pieces daily and knows the panel rules cold; design service is quoted alongside printing so you can decide with numbers.
What's the best EDDM size for design impact?
The 8.5" × 11". It's physically the biggest thing in the mailbox that day, it can't hide behind envelopes, and the extra canvas fits a menu, coupon block, or before/after set without crowding, at the same flat postage as every smaller qualifying size.
Get the Compliant Canvas Before You Design
Tell us your size and we'll send the pre-built template; send us a draft and we'll preflight it free; or hand the whole design job to our team. Start an EDDM quote, see our full EDDM service, or call (713) 882-4629.