There are many views on what image resolution is actually best for canvas printing. Let's have a closer look at this issue. In general canvas prints are designed to be looked at from quite a distant position. If that is the case we can get away with very low resolution providing the viewing distance is substantial. Most of outdoor advertising is printed from images even as low as 50 dpi - as they are designed to be seen from 10 metres+ away. But when you actually look closer you can see dots making up the image quite clearly. At this stage we need to distinguish between original image resolution and printing resolution as they are two different things. In traditional printing image is always rasterized - it is converted into series of dots with varying size usually in four colours - cyan, magenta, yellow and black. These dots placed close to each other bounce off certain wavelenghts of light creating in this way different colours. The size of the dots is determined by lpi (lines per inch) and is directly responsible for the output resolution.
In canvas printing similar process takes place - printer internally calculates where to place the dot from one of the eight colour heads and the size of it is determined by the output resolution selected by the user. But this still isn't the most important aspect - as we have control over it and can always make sure that it is done right.
There is one resolution which we as a company printing your photo do not have influence on - it is the resolution at which you send us your photo - which is in most cases same as captured by your digital camera. I have already mentioned that on our blog Taking better photos for canvas prints. It is always most sensible to choose best resolution in your camera as it may be beneficial in the future. Of course better resolution means more space on the memory card but these are really coming down in prices so honestly speaking it shouldn't be an excuse :-).
The hard formula for the canvas printing is to have 100 dots per inch (dpi). So for 12"x16" canvas ideally we should have 1200x1600 pixels image. More on resolution also on our Canvas Resolution Guide page. Your image contains specific amount of pixels which predefines the right size when it comes to printing. It has been a rule of thumb that on average 100 dpi should be optimal value.
In our experience more flexible approach also works. As canvas prints are intended to be viewed at significant difference (not less than 0.5m) even smaller than 100dpi resolution is also fine. It also depends a lot on actual photo contents i.e. if a subject has lots of sharp details then enlarging it will cause loss of quality. Our new canvas prints ordering system is actually calculating effective resolution based on your selected canvas size as well as magnification level. It helps to assess very quickly what size will be appropriate for your photo. Our staff always checks your particular image even after order have been placed and we will always contact you if we think that selected size may not be appropriate.
Here is a example of impact on photo quality caused by enlarging the photo above its optimal resolution.