FAQ
Blockbench: UV Mapping
Definition
A UV map or just "UV" is the information in a model, which parts of a texture are shown on which parts of a model. UVs can overlap and hence cause several parts to use the same area on the texture.
Editing a UV Map
You can edit a UV-map trough the UV window in the top left.
Make sure to have a cube selected which you want to UV map and freely resize/move the selection box in the UV window.
You cannot resize the UV selection if you're using Box UV
What do the value fields below the UV window mean?
Per-face UV: The first two values are the x/y position (with 0/0 being in the top left
corner) of the UV map, and the last two values its width and height.
Box UV: The 2 values are the x/y position of the UV map. The size of the UV map depends on the size of the respective cube.
I don't wanna bother with any of that, just let me draw on the model!:
Select all elements (Ctrl+A) and, create a new texture and make sure to select "Template" as type.
This will create a new texture that will keep already existing texture information, but assigns each element a unique section in the texture.