Start with the wall, not the print

The mistake most people make is choosing a size first and a wall second. Reverse the order. Measure the wall in centimetres, note anything that competes with the canvas, such as a door frame, radiator or shelf, and subtract that space. What remains is your working area. A canvas should fill roughly two thirds to three quarters of it. On a bare 200 cm wall, that means a canvas between 130 and 150 cm wide reads as intentional rather than lost.

Height matters as much as width. A landscape canvas hung too high is the most common error, and the fix costs nothing. The centre of the image should sit about 145 cm from the floor, close to average eye level. If the canvas hangs above a sofa or sideboard, leave 15 to 25 cm between the furniture top and the bottom edge of the frame. Less than that and the two feel cramped. More and the canvas floats away from the room.

Match the format to the composition

Jonsson painted Icelandic landscapes, and landscape format suits most of them. A wide horizontal canvas suits a long wall above a sofa or bed. A vertical canvas, less common in his work, works better in a stairwell, hallway or the narrow wall beside a window. Square formats are the hardest to place. They need a wall with clear space on both sides, or they read as an afterthought.

It also helps to know what the painting itself contains before choosing scale. A canvas built around a broad sky and a low horizon carries a large size well, because the composition expands rather than tightens. A tighter scene with heavy foreground detail can feel oppressive at 120 cm. The guide to Jonsson's most frequent subjects what subjects he painted most often covers this in more detail and is worth reading before you settle on dimensions.

Test before you commit

Paper is cheaper than canvas. Cut a rectangle of newspaper or wrapping paper to the exact dimensions you are considering, tape it to the wall, and live with it for two days. Check it from the doorway, from the sofa, and at night under lamplight. Almost everyone adjusts the size at least once after this test, usually downward. A canvas that looks modest on paper often looks larger once it carries an image.

If the test reveals the wall is smaller than you thought, resist the urge to abandon the idea. A 60 to 80 cm canvas, properly hung at eye level and given clear space, often works better in a small room than an oversized piece. The same logic applies to pairing a canvas with framed pieces. If you are weighing formats rather than sizes, the comparison of canvas and framed poster prints choosing between canvas and framed poster sets out the practical differences.

One last check concerns the room itself. Jonsson's palette runs cool, all grey water and pale northern light. In a small room this can recede pleasantly or feel cold, and size changes that balance. A larger canvas in a small bedroom, for instance, can dominate. Guidance on prints for small bedrooms prints suitable for small bedrooms applies here even though it addresses a different artist, because the sizing principles are the same.