Postcard Strategy & Creative
What Postcard Size Is Best for B2B Direct Mail?
Yotru runs four postcard formats: Small (4.25" × 6"), Signature (6" × 9"), Jumbo (6" × 11") and Extra Large (9" × 12"). Signature is the default for most cold B2B outreach because it balances physical presence, creative room and cost per piece. The other three formats earn their place at the edges: Small for warm, low-effort touches at high volume, and Jumbo or Extra Large when account value or message complexity justifies the added cost.
Practical guide · Published August 22, 2026 · Written by Zaki Usman
The four formats at a glance
Every Yotru campaign runs in one of four sizes. Small is the compact, low-cost option built for messages that don't need to do much convincing. Signature is the middle ground and the format most campaigns should start from. Jumbo adds meaningful extra space without moving into premium print territory. Extra Large is the largest format, closer to a mini print piece than a standard postcard, reserved for accounts where a heavier physical statement is worth making.
The right way to think about size is not "biggest wins" or "cheapest wins." It's a match between the format and three things: how much the recipient already knows about you, how much the account is worth if the campaign works, and how many pieces you need to mail to hit a volume that produces reliable results.
How the formats compare
| Format | Dimensions | Area | Typical use case | Relative cost per piece |
|---|---|---|---|---|
| Small | 4.25" × 6" | 25.5 sq in | High-volume prospecting, simple single-message offers, warm follow-up and re-engagement | Lowest |
| Signature | 6" × 9" | 54 sq in | Most cold and warm B2B outreach, the default starting point | Moderate |
| Jumbo | 6" × 11" | 66 sq in | Higher-value account tiers, later-stage touches, messages with more than one point to make | Higher |
| Extra Large | 9" × 12" | 108 sq in | Executive outreach, strategic accounts, campaigns where a heavier physical presence matters | Highest |
Cost varies by paper stock, finish, quantity, geography and mailing specifications, so treat "relative cost" as a ranking rather than a fixed multiplier. What's consistent across print vendors is the direction: bigger formats cost more per piece, both to print and to mail, and that gap is worth confirming against current rates before locking in a budget.
A framework for choosing
Three questions do most of the work in picking a format. First, what does the recipient already know? A list that's never heard of you needs more room to make the case than a list you've already touched once. Second, what is the account worth if this works? A campaign aimed at enterprise accounts can justify a cost per piece that wouldn't make sense against a broad SMB list. Third, how many pieces are you mailing, and does the format keep the economics sound at that volume? A campaign that needs to reach several thousand accounts to produce a reliable number of conversations has different cost tolerance than a narrow list of a few hundred named accounts, even though direct mail campaigns generally work best planned in the low thousands of pieces or more.
Why a run stays on one format
Whatever size you land on, a single production run should use that one format throughout. Mixing sizes within the same print job adds handling complexity and cost without a real upside. If a list has a distinct top tier that justifies a bigger format, that tier gets produced as its own separate, single-format run, not folded into the main mailing with a handful of oversized pieces mixed in.
Where to go deeper
This article is meant as a map, not the final word on any one format. For a direct comparison between the two middle formats, see 6×9 vs. 6×11. For the specifics of when Small makes sense and where its limits are, see When to Use a Small Postcard. For the cost-justification logic behind stepping up to Jumbo, see When Is a Jumbo Postcard Worth It?. For the top end of the lineup, see When to Use an Extra Large Postcard. And for the broader question of whether size itself moves response rates, see Does Postcard Size Affect Direct Mail Response?.
Frequently asked questions
Signature, 6" × 9", unless there's a specific reason to move up or down. It works across the widest range of audiences and offers and keeps cost per piece manageable at real campaign volume.
No. Bigger buys more physical presence and more room for message, but it doesn't fix a poorly targeted list or an unclear offer. Match size to account value and campaign stage rather than defaulting to the largest option.
Yes, but only as separate tiers, not mixed within one production run. A common pattern is running a broad list in Signature and a smaller, higher-value tier in Jumbo or Extra Large as its own separate run.
Look at whether the whole segment you'd run at that size is uniformly high-value, not just a handful of accounts, and whether it's large enough to run as a coherent campaign on its own, generally in the low thousands of pieces or more.
No. QR codes, unique tracking and recipient personalization work the same way across all four formats. Size mainly affects how much room there is for supporting message and imagery, not which features are available.
Related topics
Work with Yotru
How Yotru approaches format selection
When Yotru scopes a new campaign, format is one of the first decisions we make, and we default to Signature until the list or the offer gives us a specific reason to move. We ask about account value, campaign stage and volume before recommending a step up to Jumbo or Extra Large, and we'll flag when a list is better served by splitting into tiers rather than forcing everyone into the same format. .