why?

[civic gazelle]

why does this happen and how can I paint pixel by pixel?

[ornate lava]

Welcome to the help forum!

Please make sure to read #1029373817119838218 as it may answer your question!

Once your question has been resolved, please mark the post as closed by using the </close:1163944441741049897> command.

[fading quarry]

because this is your texture

!faq uv-mapping

[ornate lava]

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.

[fading quarry]

delete the texture and create a new one, clicking the template option

[worn rune]

If you wanna make a texture use the Image format, not a model format.
You can tell the game later to make a model out of that texture