 So you made a smart material and you wish there was a way to save it so you can just drag it into future projects later on. Not a problem. Hopefully you have named all of your layers and organized them beautifully so they're easy to understand. Once you've done that, make one big folder, give it a name, and drag everything into it. Then right click, create smart material, you're done. Now every time you open a substance, your smart material will appear in the library. Now when I name my smart materials, I always put a C at the beginning which stands for custom because it makes it really easy to find later on when I want to find it in the library. But you can use whatever naming convention you want, just be consistent. And last keep in mind that your materials are dependent on your shader. I always use metallic roughness with alpha blending so most of my custom materials are designed with that shader in mind. It's not really a problem if you always use the same shader, but if you use lots of different shaders all the time, you might want to designate the shader your material is supposed to be used with in the name when you create it. Otherwise I hope that helps and as always, I hope you have a fantastic day and I'll see you around.