Spoiler alert - the answer is Alien Alloy. This insanely rare alien material is used to get only the best upgrades, and each one is hidden in a special location. You can't "farm" the alien alloy, but you can find it very quickly if you know exactly where to look. There are two alien alloys that I'm going to explain here, and both require the Jump Thruster upgrade to reach, so you'll need to at least make some progress.
How to Get Double Jump and Grapple Upgrades
How to complete the quest "Fixer Upper" | Foreign alloy location
To complete the 'Fixed upper“Quest, one of the first quests in the game, you will have to find an alien alloy. These rare crafting materials are used to get the best 3D printer upgrades, and you will only be able to access the upgraded 3D printer blueprints after you bring back at least one alien alloy.
There are two easy-to-reach alien alloys near the start of the game in the landing site area. You will need the Upgrading Jump Thruster to access both.
Alien alloy # 1: Towering Crystals Of Madness - From the Verdant Wilds of Zyl, walk the left path until you reach the teleporter near the Towering Crystals of Madness. From here you can find the sparkling cave of wonder. Look to the right for a narrow opening that you can jump over.
Crawl inside and you'll find a room filled with lava. You will need to time your jumps to land on the platforms as they emerge from the puddle. You won't instantly die of the magma, but you will want to avoid it as much as possible. Jump through space and you can reach an alien alloy from the plant container.
Alien alloy # 2: Tranquil Crevasse of Tranquility - From the verdant expanses of Zyl, follow the path back to the right to the towering alien statues. Use the double jump to cross the Crevasse of Tranquil Tranquility. Hit a Pufferbird in the Meat Vortex to unlock the spin gate and follow the path to the right.
Go through two more meat whirlwind barriers until you reach a high plateau with a teleporter installation. Unlock it, then follow the path to an even higher plateau nearby - it's directly in front of the teleporter. Above you will find a large arena guarded by Pikemanders. They are tough enemies, so be prepared for a fight.
Use the dodge ability with your jump thruster to dodge their quick wheel attack, then aim and shoot the glowing orange spots on their tail. Kill one and two more will appear. Once you've killed these two minions, the plant in the center of the arena will reveal a precious alien alloy.
