If you have ever set up a market stall at 6am and watched people walk past without a second glance, the problem is usually not your produce. It is the sign. A stall banner has about two seconds to do its job, and most of the ones I see are designed on a laptop at midnight and never tested against actual daylight.
You can build a much better one in an afternoon if you treat it as three separate layers instead of one image. I use aiimagegenerators.net for the background and texture layers, then drop the type on top in a plain editor. That split is the whole trick.
Start With the Reading Distance, Not the Design
Before you prompt anything, pace it out. Stand where a customer would first notice your stall and look at a blank sheet taped to a pole. A sign 3 metres away needs letters roughly 2.5cm tall. At 10 metres you are looking at 8cm. Most stall signs are designed for a distance of about half a metre, which is why they look like confetti from the aisle.
Write those numbers down. They will stop you from making the single most common mistake, which is filling the banner with a menu. The menu belongs on a small card at eye level. The banner is a name, a category, and maybe a price hook.
Layer One: The Background
The backdrop needs to be boring in the best way. It should survive being printed on cheap vinyl and viewed at an angle in harsh sun. That means low contrast, muted saturation, and no fine detail.
A prompt that behaves well: "flat background texture, warm weathered wood planks, soft even lighting, low contrast, no text, no logos, wide horizontal composition." The important words are low contrast and no text. Generation tools love to sneak in signage, and a fake sign inside your sign is a disaster.
If you are selling produce, a subtle paper or kraft texture also works. If you are selling crafts, a fine linen weave reads as handmade without shouting. Run four or five variations at the largest aspect ratio you can, then pick the one with the flattest tonal range. You want the type to sit on it, not fight it.
Layer Two: The Accent Shape
This is where most people stop and where most signs go wrong. You need one simple block of colour behind your name so the type has something solid to sit on. A rounded rectangle, a soft arch, a torn-paper strip. One shape, that is it.
Prompt it separately on a plain white background: "single solid rounded rectangle block, deep red, flat colour, no shadow, no gradient, centred, white background." Then cut it out and place it. Keeping this as its own layer means you can reposition it without regenerating the whole thing, which saves you an hour of retries.
Layer Three: The Type
Do not generate your text. Ever. Generated lettering has wrong letterforms, stray marks, and inconsistent spacing, and at banner scale those flaws are the only thing people will see.
Set the name in a heavy sans-serif, all caps, tight tracking. A second line underneath in a lighter weight for the category. That is your entire hierarchy. Two type sizes, one font family. If you feel tempted to add a script accent for charm, put it on the price card instead.
The Sunlight Test
Print a full-size proof on plain paper, tape it to a window, and stand on the other side of the room. Whatever disappears is what you remove. Colours that look rich on screen, especially deep purples and dark greens, tend to collapse into mud in direct sunlight. Warm reds, oranges, and near-blacks hold up best.
Small Details That Save You Later
Leave a 5cm empty margin on all sides. Printers trim, and grommets eat corners. Build the sign at 150dpi at final size rather than scaling up a small file, because stretched type gets soft edges that read as blurry from ten metres. And add your stall name to the bottom corner at small size so it stays visible if the banner gets cropped in a photo someone posts later.
Once you have your layers saved, you can swap the colour block for a different market, or reprint with a seasonal name change in about ten minutes. That is the real payoff of building it in pieces.
If you want to run the background and accent passes yourself, the free tool at aiimagegenerators.net handles both without an account, and you can export at full banner resolution. Start with the reading distance, build the three layers, and test against a window before you pay for vinyl.