A reference board is not the same object as a comparison grid. Its job is to carry a direction: the palette, the light, the texture, the silhouette, the kind of framing you want. That is why coherence across the cells matters more than the resolution of each one. A board reads as a style when the images share something, and reads as noise when they do not.

Two rules cover most cases. First, an even number of cells in a rectangular layout: 2×2 for four references, 2×3 for six. A rectangular board is simpler to describe in a prompt and less likely to be read as a collage of unrelated parts. Second, a visible gutter: about 8px of separation so the tool sees distinct panels rather than one blended image.

Two board types are worth keeping apart. A style board gathers images that share a treatment: four shots with the same grain and the same light, or six images that carry the same colour range across different subjects. A subject board gathers one thing seen from several angles: four views of one object, or six frames of a character in different poses. Mixing the two types is what produces boards that describe nothing in particular. For more on how a layout steers a model, see image grid for AI prompts.

Order matters more than people expect. Put the reference you trust most in the top-left cell, then the ones that support it, in decreasing order of importance. A board is read the way a page is read, and that same informal rule applies when you refer back to it later.

Export at 2048px on the longest side: high enough that texture and edge detail survive, small enough that you can keep several boards side by side. PNG preserves gradients and fine grain better than JPG, which is the usual reason to prefer it for a style board. On the free plan you have 4000px available if a board needs to be larger, and 2 exports per day, which is the practical limit when you are iterating on several directions.

Everything is composited in your browser, and that matters here: reference images are often work that is not public yet. The free plan covers 12 images per grid, PNG and JPG output and no account. The 24-hour Pass at $3 removes the daily export limit for 24 hours and adds PDF and WebP output if the tool you use prefers WebP.