This study compares two types of stationary phases, conventionally-coated and chemically-bonded, for use in high speed liquid chromatography. Conventionally-coated phases are liquids (or solids) deposited on a solid support and held by physical forces. Chemically-bonded phases are liquids (or solids) chemically attached to the support material and oriented like bristles on the surface of the support. At the same weight per cent of stationary phase, the capacity factor (k′) for several test solutes was found to be equal for both chemically-bonded and conventionally-coated stationary phases. Column efficiencies (as measured by plates per foot) were found to be higher on the chemically-bonded phases. A series of different molecular weight polyethylene glycols were compared as stationary phases. Differences in polarity were observed depending upon the molecular weight of the glycol and whether it was chemically-bonded or conventionally-coated. The coefficient of mass transfer was found to increase with molecular weight of the stationary phase. Both types of stationary phases were compared using porous and solid core supports with higher efficiencies observed on the solid core supports. Advantages and disadvantages for both types of phases are included.