I changed one temperature setting and cut my 3D print failures by half

For a while, my 3D printer was reliable enough to keep me optimistic but inconsistent enough to waste plenty of filament. One print would come out perfectly, while the next would have rough overhangs, weak layers, blobs, or enough stringing to resemble a spiderweb. I kept adjusting retraction, cooling, and even the Z-offset, but the improvement just wouldn't come.