On October 30, 2026, a practitioner's account from the materials processing field disclosed the process boundaries for laser powder bed fusion (LPBF) of thin-walled parts below 1 mm. Using Ti-6Al-4V titanium alloy flow-channel parts, the author printed 10 mm-high thin walls with 200 W power, 1200 mm/s scan speed, and 30 μm layer thickness; the first build showed arc-shaped warping. Only after reducing power to 160 W, raising scan speed to 1800 mm/s, and tightening support spacing from 2 mm to 1 mm was the warpage of 0.8 mm-thick walls brought within 0.05 mm. The account shows that heat in thin-wall cross-sections cannot conduct quickly to the substrate through solidified material as in solid blocks, so the melt pool readily overheats to the vaporization point; spatter causes unmelted balls and pits in the powder bed surface. After three years of use, the actual power of the laser on the same machine model can decay by up to 15%; a 5% difference in new powder sphericity can cause 5 μm fluctuations in powder layer thickness; and contaminated protective lenses plus reduced galvanometer reflectivity can cut the power actually reaching the melt pool by 20%. Supports are explicitly described as serving heat dissipation and counteracting solidification shrinkage stress, not merely holding the part. Powder-related facts include: titanium alloy powder recovered from scrapped printed parts contained unmelted balls, and sieved support debris filled nearly half a beaker; switching to a new powder batch with different sphericity changes spreading friction and layer thickness; 0.6 mm-thick samples still showed intermittent balling traces on the sidewalls, and nearly ten parameter sets failed to find a stable window.