A series of phenol-formaldehyde resol (plywood type) resins was made with various formaldehyde to phenol molar ratios (1.70,2.00, and 2.30) and sodium hydroxide to phenol molar ratios (0.40 and 0.60). A broad viscosity range (20-1000 mPa.s) was sampled from each resin cook and characterized for pH, gel time, viscosity, alkalinity, nonvolatiles, density, molecular weight, surface tension, and contact angle. The results showed that viscosity and gel time depended on weight-average molecular weight. Condensation rate varied with formaldehyde to phenol ratio. The Cannizzaro reaction reduced alkalinity and indirectly affected viscosity and gel time. Cook procedure affected molecular weight distribution and accelerated gel times.