Whether or not you need a plumber's putty to install a new faucet depends on the type of faucet and the manufacturer's instructions.
Plumber's putty is a soft, pliable substance that is used to seal joints and prevent water from leaking out around the base of a faucet. It is typically used on non-threaded parts such as the underside of a faucet flange or the base of a pop-up drain assembly.
Many faucet manufacturers include plumber's putty as part of the installation kit, and their instructions may require its use. However, some manufacturers may recommend using silicone caulk instead of plumber's putty for a more secure and long-lasting seal.
It's important to follow the manufacturer's instructions carefully to ensure a proper and leak-free installation. If you're unsure whether or not to use plumber's putty, check the installation instructions or contact the manufacturer for guidance.
In general, if the faucet manufacturer recommends using plumber's putty, it's a good idea to use it to ensure a tight seal and prevent leaks.