Each exhibition is its own saved "instance" of a gallery — its own pieces, walls, and hangs. Use the dropdown at top to switch between them. + New exhibition starts a blank one; Load demo exhibitions restores the sample shows any time you want to see the app populated again.
In the sidebar, add pieces one at a time with a title, width, height, and a color as a stand-in for the artwork — or use Import CSV for a spreadsheet of title/width/height/color, or the Import Photos tab to point at a folder of images. Photos get an automatic thumbnail, and if a filename contains something like "1.2x0.9m", the dimensions are guessed for you.
Also in the sidebar, add a wall with its real-world width and height. Each wall gets its own tab above the canvas.
Click a wall's tab, then use the "Pieces on this wall" checklist on the right to choose what hangs there. A piece already hung elsewhere shows greyed out with a "Move here" shortcut — a piece can only be on one wall at a time, just like the real artwork.
Flow mode keeps pieces at true size and wraps them row by row automatically (or force an exact "items per row"). Grid mode divides the wall into even rows and columns. Horizontal and vertical spacing are separate controls, and you can set left/center/right/justify positioning too.
Click one hung piece in the checklist, then another, to swap their positions in the layout — no dragging needed.
Pick meters, centimeters, or inches per exhibition. Switching converts your existing numbers properly, so nothing gets thrown off if you change your mind partway through.
Use Download as PNG under the canvas to save an image of a wall's layout, or Export CSV to save your piece list.