Canvas Size Calculator

The wrap, and what it consumes

A canvas print is stretched over a wooden frame, so the image wraps around the edges and part of it is no longer facing forward.

The depth of the frame determines how much: a 20 millimetre frame consumes 20 millimetres from each edge plus a little for the fold, and a 38 millimetre gallery frame consumes nearly twice that.

Which means the visible front face is smaller than the ordered size, and content near the edge of the image ends up on the side. Faces near the edge of a photograph are the classic casualty.

Three ways to handle the edges

Image wrap continues the photograph around the sides, which looks natural and loses content. It suits images with unimportant edges: landscapes, textures, anything where the subject is central.

Mirror wrap reflects the edge of the image outward to fill the sides, so no content is lost from the front. It looks slightly odd on close inspection and is invisible from the front, which is where the piece is viewed from.

Colour wrap fills the sides with a solid colour, usually black or white or sampled from the image edge. It is the cleanest option for images with content right to the edge and it reads as a deliberate design choice rather than a compromise.

Resolution for canvas

Canvas is a textured surface that absorbs ink and spreads it slightly, which means it does not hold fine detail the way coated paper does.

The practical consequence is that canvas tolerates lower resolution than paper. Around 150 DPI at final size is generally sufficient, and 100 can be acceptable for large pieces viewed from a distance.

The texture also softens sharpening artefacts, which means files prepared for canvas benefit from less aggressive sharpening than the same image prepared for a paper print.

Preparing the file

The file needs to cover the front face plus the wrap on all four sides plus a fold allowance. For a 40 by 60 centimetre canvas on a 38 millimetre frame, that is roughly 48 by 68 centimetres of image.

Most suppliers accept a file at the front face size and generate the wrap themselves, either by extending or mirroring. That works and it removes your control over what ends up on the sides.

Supplying the full wrapped size gives control and requires knowing the frame depth and fold allowance, which varies by supplier. Their template is the reliable source and asking for it before starting saves rebuilding the file.

Scale on a wall

Canvas prints are frequently ordered smaller than the space wants, because sizes look larger on a screen than they measure on a wall.

A common guide is that a piece over a sofa should be roughly two thirds of the sofa's width, and that a piece on an empty wall should occupy 60% to 75% of the available area.

Marking the size out on the wall with masking tape before ordering takes two minutes and prevents the most common disappointment, which is a print that is technically perfect and visibly too small for where it hangs.

Gallery frames and standard frames are worth distinguishing when ordering, because the depth changes both the price and the look. A 20 millimetre frame sits close to the wall and reads as a print. A 38 millimetre gallery wrap projects and reads as an object, which suits some images and overwhelms small ones. Ordering a small canvas on a deep frame is the combination that most often disappoints, because the sides become a larger proportion of what the eye sees than the image itself.