Updated project metadata. High-resolution capillary chromatography is essential for in-depth characterization of complex biomolecule mixtures by LC-MS. We report a simple and low-cost FlashPack protocol for preparation of ultra-high performance capillary columns of > 50 cm length in less than 1 h using low-pressure equipment. Flashpack LC columns enable robust identification of >35,000 unique peptides and 5,800 human proteins in a single LC-MS analysis.