A process for packing narrow bore chromatographic columns and the resulting product are provided. A flexible column, preferably of fused silica, of inner diameter less than 500 .mu.m is selected. A slurry is formed in a reservoir from a mobile solvent and particles of specified diameter. For liquid chromatography the particle size ranges from 3 .mu.m to 10 .mu.m; for gas chromatography the particle size ranges from 3 .mu.m to 100 .mu.m. An end restriction is placed in the end of the column to permit the flow of mobile solvent and to restrict the passage of particles out the end of the column. The reservoir is attached to the column and the slurry is caused to flow under pressure into the column. A two-step pressure sequence is used to first set up the bed of particles and then to compress the bed. First, an initial pressure is maintained for an initial period, preferably less than 10 minutes. Next, the pressure is raised from the initial pressure to a maximum pressure and is maintained at the maximum pressure for a second period. The product in either case is a stable, loose packed column having a high plate number per unit length.