I've always found strange that everything is just made of pure steel, so I decided to add these new materials to the game, so that players will have to struggle and have a hard time progressing through civilizaions, and even if you do a crashlanded start, you won't start with all the necessary resources, so you'll have to look for them.
The main goal of this mod is to add a little bit of realism to the game while keeping it interesting for gameplay. The future expansion add-ons for this mod will add new interesting mechanics that will reward patience and hard work with cost-efficient benefits.
This mod adds new metals and balances vanilla recipes so that you'll have to search or craft the different materials you need to build different stuff. This mod will also act as a base for future material related mods that will add more depth (and even more difficulty xD) so if you like to make rimworld harder, you'll like these mods.