Dial in your fuller. Match your nails. Stay consistent. This 3D-printed tool is designed to help you keep your fullers tuned and your nail choices accurate. Shaped like a set of stairs, each step represents a common barstock size—½", ⅜", and 5⁄16". Three fullering lines run through each section, each corresponding to a different fuller size. Integrated nail holes allow you to quickly test and identify the correct nail size for each combination of fuller and stock. Whether you're in the shop or prepping for competition, the Fuller Guide helps you maintain clean, consistent fullering and optimal nail fit.