PaintsightDraw the same grid on your reference and on your canvas, then copy one square at a time. Each square is a small, simple drawing, so the proportions of the whole come out right.
Why it works
Copying a whole photo by eye is hard because small errors add up: a nose a little too long pushes everything below it down. A grid breaks the picture into small cells with fixed corners, so an error can't spread past its square. It also trains your eye: in one square you see shapes, angles and where a line crosses the edge, not "an eye" or "a tree".
The idea is old. In On Painting (1435), Leon Battista Alberti described a veil: a thin cloth stretched on a frame and divided by threads into squares, held between the painter and the subject, with the same squares ruled on the drawing. Painters have squared up drawings to transfer them ever since.
1. Match the shapes
Your canvas and your photo probably have different proportions. A 16 × 20 in canvas is 4:5; a phone photo is usually 3:4. Decide what part of the photo goes on the canvas and crop it to the canvas's shape first. Otherwise the squares won't match.
2. Choose the square size
Work it out on the canvas, in inches or centimeters, so the squares are easy to measure:
| Canvas | Squares | Grid |
|---|---|---|
| 8 × 10 in | 1 in | 8 × 10 |
| 11 × 14 in | 1 in or 2 in | 11 × 14, or 6 × 7 with a narrower last column |
| 16 × 20 in | 2 in | 8 × 10 |
| 18 × 24 in | 2 in or 3 in | 9 × 12, or 6 × 8 |
| 30 × 40 cm | 5 cm | 6 × 8 |
| 40 × 50 cm | 5 cm | 8 × 10 |
Smaller squares are more accurate but slower. Use them where accuracy matters most, such as a face, and bigger ones for a loose landscape. When the canvas isn't a whole number of squares, the last row or column is simply narrower.
The drawing grid maker does this for you: enter the canvas size and the square size, and it draws the matching grid on your photo and lists where to mark each line on the canvas.
3. Rule the canvas lightly
- Measure from one corner and make a small mark at every line along all four edges.
- Join the marks with a ruler or a long straightedge. Use something that won't show through: thin vine charcoal or a hard pencil for oils and acrylics, a light pencil line for watercolor or gouache.
- Number the columns and letter the rows on both the photo and the canvas, as on a map, so square C4 is easy to find on both.
4. Copy square by square
- Start with the big shapes, not details. Note where each main edge enters and leaves a square: a third of the way along the top, at the bottom right corner.
- For a detailed square, add its diagonals on both photo and canvas. They give you four more reference lines.
- Turn the photo and canvas upside down if you keep drawing what you expect instead of what's there.
- Step back now and then. The grid gets the proportions right; it doesn't make the drawing lively. Loosen the lines once the placement is right.
5. Lose the grid
Knock back charcoal lines with a soft cloth before you paint, or let thin paint cover them. In watercolor, erase pencil grid lines gently before you paint: once a wash is over graphite, it won't erase.
Sources
- Leon Battista Alberti, On Painting (De pictura), 1435, book 2, on the veil. Summary: Museo Galileo, Veil.
