The chemical and physical properties of the surface play a key role in many processes. In addition to imaging (SEM, UV-vis), in our laboratories we also measure contact angles. This method gives information on wettability of the surface. It can be used to test activity of photocatalytic coatings. Our own desined goniometers can operate under ambient or temperature and humidity controlled conditions. By assessing changes in the value of the contact angle, we can examine various properties of materials: hydrophilicity, hydrophobicity or photocatalytic activity.