Only particles of intermediate hydrophobicity (apparent contact angle values θ between 110 and 152°) are able to form stable emulsions. For pigments with apparent values of contact angles between 129 and 152° emulsions can be catastrophically inverted from a w/o- to a o/w-emulsions by an increasing volume fraction of water. The volume fraction of water which is necessary for the process of phase inversion is a direct function of the particle hydrophobicity. The long-term stability of the oil-in-water emulsions decreases, whereas the stability of water-in-oil-emulsions increases with increasing apparent contact angle values against water.