packing in column chromatography, in chromatography

https://dx.doi.org/10.1351/goldbook.P04394
The active solid, stationary liquid plus solid support, or swollen gel put in the column. The term packing refers to the conditions existing before the chromatographic run is started (i.e. to the material introduced into the column), whereas the stationary phase refers to the conditions during the run.
Source:
PAC, 1993, 65, 819 (Nomenclature for chromatography (IUPAC Recommendations 1993)) on page 831