Postcards
What it is
Postcards are thanks.io's most popular mailer type. They are full-bleed, printed cards available in three sizes: 4×6, 6×9, and 6×11 inches. Every postcard supports a custom front design, a handwritten-style message on the back, and optional QR codes.
When to use it
- High-volume outreach campaigns where cost per piece matters
- Neighborhood farming and real estate geographic targeting
- Promotional offers, limited-time discounts, and event announcements
- Post-purchase thank-yous and customer retention
- Drip campaigns and evergreen marketing sequences
Postcards are the best starting point for most users - widest selection of inspirations and ready-made designs, lowest per-piece cost, and they support every automation feature on the platform.
Choosing your size
4×6 - the most cost-efficient size. Best for high-volume sends where per-piece cost is the primary factor.
6×9 - significantly more visual presence in the mailbox than 4×6. Popular for real estate agents, local service businesses, and campaigns where the design needs room to make an impact.
6×11 - the largest postcard format. Maximum print area for bold imagery, luxury branding, and event announcements.
Each size is a separate choice on the first step of Send Mail and when you make a new creative.
Design specs
| Size | Full-bleed canvas | Safe zone |
|---|---|---|
| 4×6 | 1875 × 1275 px | Keep content 10% from each edge (~188 px left/right, ~128 px top/bottom) |
| 6×9 | 2738 × 1838 px | Keep content 10% from each edge (~274 px left/right, ~184 px top/bottom) |
| 6×11 | 3337 × 1777 px | Keep content 10% from each edge (~334 px left/right, ~178 px top/bottom) |
The design previews in Creatives and Send Mail draw these zones over your artwork:
- Cut line (red) - the outer edge of the printed card. Artwork should extend past this line (bleed) so there are no white borders after trimming.
- Safety zone (blue) - the inner safe zone. Keep all important content - text, logos, contact info - inside this line.
- Address and postage (gray, message side) - where thanks.io prints the addresses and postage. Keep it clear.
See Print Specs & Safe Zones for the full reference across all mailer types.
Creatives for each size
Each postcard size is its own mail type with its own creatives and its own default message background (set under Branding → Branded designs). A creative made for one size is not offered when you send another, so every design you pick is built for the canvas it prints on. In Creatives, the 4×6, 6×9, and 6×11 postcards each have their own tab, and you choose the size when you click New creative. To reuse a design at another size, make a new creative for that size.
If you upload a front at the wrong dimensions for its size, thanks.io saves it cropped to fit and shows a warning. For the best print quality, upload at the exact canvas size above.
6×9 campaigns and sends set up with a 4×6 postcard design continue to send with that design. When you create or copy a 6×9 campaign, choose from your 6×9 creatives.
Design tips
- Full bleed: extend artwork to the edge of the canvas (plus bleed margin) so there are no white borders after trimming.
- Safe zone: keep important content (text, logos, contact info) inside the safety zone shown in the preview.
- Resolution: use high-resolution images at the exact canvas size above.
- QR code placement: the message side reserves space for the address block. Don't place the QR code in the address area.
- Top-right message area: if you want content above the address block on the back side, add it through the custom message background image. The handwriting engine does not place text there.
Personalization
Use replacement variables in your message (click Personalize in the message editor to insert them):
%FIRST_NAME%- recipient's first name%YOUR_COMPANY%- your company name%CUSTOM1%through%CUSTOM10%- custom fields from your mailing list
Choose one of the AI styles (AI Fonts) and optionally set Realism (Realism Mode) to make the handwritten-style rendering look more natural.
Tips & best practices
- Run Check my message before sending. A clear CTA and a personal opening line consistently drive better response.
- Use 6×9 or 6×11 for campaigns where you want to make a strong first impression.
- Add a QR code so you can track who responded.
- For time-sensitive campaigns, select First Class postage to reduce delivery variability.
Limits & gotchas
- Design spec requirements (bleed, safe zone) vary slightly by size - check the zones drawn on the preview.