Free and customizable UV mapping texture made in Blender and shared under Creative Commons Attribution 4.0 International License. Which means, you may use it for free, modify and adapt, but have to credit the original author. Please, leave a link to this repository and the author name in credits section of your app or content pack, created with this texture.
The texture has soft gradient which makes working with it easier for your eyes even for hours in a row. I've tried to balance out the amount of color on the final image to preserve visibility of geometry details and issues that can be missed on pure gray or too vivid UV textures.
Since I'm using it for real-world structures and following metric-systems in mind, the default UV image has extended grid of 10×10 marked cells (instead of 8x8), and also .5 and .1 lines to allow scale-perfect texturing.
But with feedback and requests from people, I've also added the traditional 8x8 (so people can follow their usual workflow with power of 2 in mind)
The Blender 4.2 file is also attached, so you can modify it for your needs or render in any resolution (if 4K is not enough). There are two cameras (one for 10, and one for 8 cells, and two sets of tiny grids.
For casual users unfamiliar with GitHub: just press green button over the list of files above and save as ZIP.