Go grab some free goodies from Maurus Kamehameha.
The artist faced a problem: he didn't have the UV checker maps he needed. "The ones I've found on the interwebs were either in a too low resolution, watermarked, or hadn't had enough markers and symbols for orienting," wrote the developer.
Maurus created a UV checker map himself by combining 3-4 other checker maps. These new maps are 100% free, open-source, and scaleable.
The artist shared a set of four and uploaded them to a Google Drive as 4K PNG, 8K PNG, vectorized PDF, plus an editable Illustrator project in case you want to modify the maps.
You can get the maps here.