This is a very common question and depends on a number of factors such as the type of camera you use to take photos, how far away you are going to be viewing the image and what surface you chose to print your image onto.
Our Canvas App software allows you to select a size and view your image at print size. This will give you an indication of whether your image is suitable for the size chosen.
If you are unsure and need help, you are welcome to email your image to our Support Team, and we will be able to recommend a size.
We do find that canvas material is a lot more forgiving than other mediums. Glossy paper for example shows off a lot more detail, whereas canvas material allows the ink to be absorbed more, blurring the pixels slightly and allowing you to get away with a lower quality image.