The ground is what the sheet lies on. You see it all around the sheet and through every hole cut in it. The card calls it “Ground”; the prompts about taking or putting back paper call it the background. A new design starts on a white ground.
What it does
The ground color fills everything that is not paper: the margins around the sheet, the holes in it, and the gaps between the flipped pieces. On the canvas it is the color of the canvas itself, behind everything else that is drawn.
A hole always shows the ground. Pieces land outside the sheet, and even in the exported artwork a sheet-sized patch of ground is laid under the sheet, so a piece that strays back over it cannot show through a hole.
When a shape you draw covers both paper and a hole, the app asks whether to take the paper or put paper back. Its prompt says: “This shape covers paper and background.” That background is the ground.
The artwork export, as SVG or as a 300 dpi PNG, is painted on a frame three sheets wide and four tall, filled with the ground color. The ground is part of the picture, not a gap in it.
With nothing locked, a harmony keeps the ground pale (low saturation, high brightness), because the ground is what the sheet is read against. In the harmony order, Front, Back, Ground, the ground comes last. Its card has a swatch, the name “Ground”, a hex code, a padlock and sliders, like the others.
Why it works this way
A real paper cut is always seen against something: a table, a wall, a mount board, a window. That surface is part of the design whether you choose it or not, so the app makes you choose it. Giving it its own color, rather than assuming white, lets a notan sit on black, on a mid gray, or on a color that ties the front and back together.
The hole shows the ground rather than whatever piece lies under it because in paper that is what happens: pieces are flipped out, beyond the sheet's edges, and a hole looks straight through to the surface below.
The metaphor
“Ground” carries several meanings at once, and each fits a little. In painting, the ground is the prepared surface a picture is painted on: gesso, or a thin toned layer the painter works over. In etching, the ground is the acid-resistant coating the artist draws through with a needle. In perception, since Rubin, the ground is the region that seems to run on behind a figure. And plainly, it is the earth, or the table, underneath.
The metaphor holds best in the perceptual sense: the ground is whatever is not the figure. It breaks in the painter's sense. A painter's ground is usually covered, showing only in glimpses between strokes; here the ground is never painted over, only uncovered where the paper is not. And it has no edge. A real mount board ends somewhere; the app's ground runs out to the edge of the window in every direction.
A history
In art
In 1915 the Danish psychologist Edgar Rubin defended a doctoral thesis at the University of Copenhagen on visually experienced figures, and in it described the relation that gives this color its name. Where two regions share a border, one is seen as the figure, shaped by that border, and the other as ground, continuing behind it. His vase that is also two faces made the idea famous, and the Gestalt psychologists built on it.
Artists had worked with the ground long before it had a theory. The oldest dated pictures we have are figures made of ground. A hand stencil is made by pressing a hand to rock and blowing pigment around it; the hand is the part where color did not go. In Argentina's Cueva de las Manos, most of the stenciled hands are between about 9,300 and 7,300 years old. On the Indonesian island of Muna, off Sulawesi, a stenciled hand was reported in 2026 to be at least 67,800 years old, the oldest reliably dated cave art yet found. A hole in a notan works the same way: a figure made of the ground.
In printing
In most printing the ground is the paper, and printers call its color paper white: it is the lightest color in any print on it, and every ink is judged against it. Chiaroscuro woodcuts of the sixteenth century cut gaps in their tone blocks so the paper would show as highlights, making the ground one of the picture's colors on purpose.
The stencil carried the hand-stencil idea into printing. Pochoir, the French stencil process that flourished in Paris in the early twentieth century for fashion plates and design portfolios, laid color through cut stencils one at a time, and screen printing does it still with a stencil on a mesh. And in etching the word ground has its technical meaning: a thin waxy coat on the copper plate, drawn through with a needle, so that acid bites the plate only where the ground has been removed.
In technology
Digital pictures had to learn what a ground is. In late 1977, at the New York Institute of Technology, Ed Catmull and Alvy Ray Smith made transparency part of every pixel: the alpha channel, recording how much of each pixel is covered and how much lets the ground through. In 1984 Thomas Porter and Tom Duff published the mathematics of laying one image over another, including the operation they called over. The four shared a technical Academy Award for digital compositing in 1996. Image editors still show transparent pixels as a gray and white checkerboard, a ground drawn to say there is no ground.
Film had solved a version of the problem earlier. For The Thief of Bagdad (1940), Larry Butler used a blue screen to separate actors from their background so a new one could be put behind them, and shared the Academy Award for special effects. A blue screen is a ground made to be replaced. In Studio Notan the ground is the plainest version of all: the background color of the canvas the design is drawn on, showing wherever nothing else has been drawn.
In professional software
Professional programs call the ground the background, the canvas, the artboard or the paper, and most treat it as empty until you say otherwise. The habit to take from Studio Notan is to choose it on purpose, because the ground is part of the picture.
- Adobe Photoshop. A new document’s ‘Background Contents’ can be white, black, the background color, a custom color or transparent. Transparent pixels show as a gray and white checkerboard, whose size and colors are set in the ‘Transparency & Gamut’ preferences.
- Adobe Illustrator. The white of the artboard is not painted. ‘View › Show Transparency Grid’ (⇧⌘D, or Shift+Ctrl+D on Windows) shows that it is empty, and ‘File › Document Setup’ has ‘Simulate Colored Paper’ for previewing a colored stock. For a real ground, draw a rectangle on the bottom layer.
- Adobe InDesign. The ‘[Paper]’ swatch stands for the stock. Set it to the color of your paper and the screen preview follows, but no ink is printed for it: anything filled with it simply lets the sheet show through.
- Autodesk AutoCAD. The drawing area is dark by default, and its color is set with the ‘Colors’ button on the ‘Display’ tab of ‘Options’. It is a working ground only, and it is not plotted.
- Figma. The canvas color is only a workspace. What you export is usually a frame, and a frame with no fill exports as transparent, so give the frame a fill if the ground belongs in the picture.
What carries over. A transparent ground is not a white one. A PNG exported with transparency takes on whatever lies beneath it: a dark web page, a colored card, a tabletop. Decide whether the ground belongs in the file, as it does in Studio Notan’s artwork export, or is left to the place the work will be shown, and check the result on the color it will actually meet.
Try this
- Set the ground to a mid gray. Both the black sheet and a white back would now read against it.
- Give the ground the same color as the front. The holes vanish; only the flipped pieces show.
- Give the ground the same color as the back. Now the pieces vanish and only the holes show: the two halves of a notan, one at a time.