When a model's uv values are fractional, there can be rendering issues with the model where, while tiling/stitching, you can see a grid of where some bits of the texture that were not set to show, will show far away from you between the blocks. This also can be seen in item models, where the edges of the model do not connect to each other or thin lines are showing on the edges.

To test:

1. Download the provided resource pack
2. Make a floor of stone blocks
3. Notice the grid between the blocks