Water-Alcohol Mixture is a mixture of (preferably distilled) water and alcohol (usualy methyl, ethyl, or isopropyl.) It is usually used whenever a water soluble binder is being dissolved/activated. The alcohol in the mixture makes the water effectively wetter by lowering the surface tension of the water. The mixture also dries slightly faster than plain water.
Concentrations of alcohol in the mixture typically range from 5% to 25%. Generally, when more than 25% alcohol is used it stops being effective to disolve/activate water soluble binders.