I would like to make a texture for a freshly created cube.
i hope it will tile, with one copy of the texture on each side.
But I am confused what pixel width and height to use in photoshop to make it.
The cube is unchanged and fresh, so scale is 1 for everything…so, what does this represent in pixels please?
That’s not the way texturing works: usually each vertex in a 3D model has a UV pair associated. This UV pair contains two coordinates in the range 0…1 that tells which point of the texture is “glued” to it - 0 means left or bottom and 1 means right or top (or the contrary, I’m not sure), no matter how big or small the texture is.
You can draw your texture in any size, because it will be mapped to the model vertices. In a standard Unity cube, the UV coordinates are 0,0 at one corner and 1,1 at the opposed one, thus you will have the full image in each cube side. Usually sizes range from 128x128 to 4096x4096 - higher resolution produces better images, but occupy more video card memory and take more time to be uploaded, thus you must find a good compromise.