When creating a mosaic from a picture, the small details are replaced with mosaic tiles. It’s clearly visible on Vincent van Gogh’s self potrait how the details become more defined as pictures with higher resolution are created.
If we intend to hang the picture on the wall, it’s good to know the ideal picture proportions for developing it in which sizes at a good quality, shown by our following two posts:
Recommended mosaic resolution for creating posters (cm)
Recommended mosaic resolution for creating posters (inch)
It’s possible to develop a high resolution picture in a small size, but it means that some of the details will also be smaller on the developed picture.