We had some leftover cedar tongue and groove board ends at work from a door building project. They looked suspiciously like the salmon grilling planks you can buy for your grill. I ran them through a thickness planer to smooth them and cut the groove side off on the table saw. The brand was made from a leftover piece of brass weatherstripping. I bent it into the spiral design and heated it over a small gas barbecue grill with pliers. I used a piece of scrap wood to press down on the brand once it was hot.