Many jurisdictions (counties, states, provinces, etc.) have brand books that list the registered brands. Some of these books are available on the web and go back many years. I have found and identified registered brands for my parents, grand parents, and other relatives and friends. Some example links:
https://archives.utah.gov/research/digital/brand-books/
https://archive.org/details/utahbrandbook00salt
https://archive.org/details/albertasaskatche00albe
https://archive.org/details/officiallivestock1970albe
Do a google search for the location and brand books and maybe even the year you want. Some libraries have bound copies of local brand books.
A few years ago I looked up brands for a friend from Utah. It included sheep ear cuts that were registered. Found a few from her family. Made coasters featuring cattle and horse brands and sheep ear cuts related to ancestors.