Generating header and section images for email newsletters

The two image jobs in a newsletter

A newsletter uses images in two different ways. The header sits at the top and sets the tone before anyone reads a word. The section images sit between blocks of text and give the eye somewhere to rest in a long issue.

They have different shapes. A header is wide and short, often the full 600-pixel content width by 150 to 250 pixels tall. Section images are usually the same width or smaller, square or landscape, placed inline with the copy.

The thing readers notice most is consistency. When every issue opens with the same style of header and the same treatment for section art, the newsletter starts to look like a place rather than a one-off email.

Sizing images for the inbox

Most newsletters render inside a content column about 600 pixels wide. To stay sharp on high-density phone and laptop screens, generate at twice that, around 1200 pixels wide, and let the email display it at 600. The client scales it down and the edges stay crisp.

Nano Banana 2, the image model behind Figgshield, renders at 1K or 2K for 8 credits, or 4K for 16. For a 600-wide column, 2K gives you enough resolution to crop to the exact header ratio and still keep detail to spare.

Watch the file weight. Email images load from a remote server every time the message is opened, often on mobile data, so a lighter file feels more reliable. Gmail also clips a message once its HTML passes about 102 KB, so keep the markup lean and let the images do the heavy lifting from their host.

Generating them from your writing tool

Figgshield is an MCP server at https://api.figgshield.ai/mcp. Connect it once in Claude, Claude Code, Cursor, Windsurf, ChatGPT Developer Mode, or any other MCP agent, and you can ask for images in the same window where you draft the issue.

A header prompt can be plain: A 1200x400 email header, soft morning light over a desk with coffee and a notebook, warm and calm, room for a short title in the top left. For a section image, describe the idea in the paragraph it sits next to so the art actually matches the copy.

To keep the look on brand, send a reference image, a past header or your logo, and ask the agent to follow its palette. That file is used in memory to guide the generation and is never stored, so an unpublished asset is safe to pass.

Alt text and the images-off inbox

Many inboxes hide remote images until the reader clicks to load them. Outlook does it, and plenty of people leave that setting on. If your header carries the only greeting, or your call to action lives inside a picture, those readers see nothing.

Give every image real alt text that says what it shows, and never put the call to action only in the image. Keep the button and the key line as live text so the message still works with images off.

Set a background color on the header cell that sits behind the image. When the picture has not loaded, a reader sees a colored band with your alt text instead of a broken-image icon on white.

Hosting so the header doesn't vanish

Every file Figgshield generates lives on a private link for 7 days and is then deleted. Email is the worst place to depend on a link like that, because the client fetches the image fresh on every open, including opens weeks after you sent the issue.

Download the file and upload it to your email platform's own image host, the content library in Mailchimp, Substack, Beehiiv, or Kit, or to your own bucket or CDN. Then the <img> tag points at a URL that stays alive as long as the archive does.

Testing headers and what it costs

Marketers already test subject lines. The header is just as testable, and generating a second version costs almost nothing here. Ask for two or three header variants in one conversation, send them to small splits of your list, and keep the one that earns the most clicks.

One credit balance covers images and video, and Figgshield charges at cost with no markup on the models. If you want motion for the browser version or a social teaser, turn a header you already made into a five-second clip by passing its image id to Kling 3 or the faster Kling 3 Turbo, for 35 credits.

The $5 seven-day Pro trial comes with 150 credits, about eighteen images at 1K or 2K. Cancel before day 7 and you pay nothing more. There is no free tier. See how credits work for the full breakdown.