"A glaze is simply a thin, transparent layer of paint and glazing is simply building up color by applying thin, transparent layers one on top of another, dry layer. Each glaze tints or modifies those beneath it. So why is glazing something that can trouble, and even threaten, artists so much? Well, while the theory may be simple, putting it into practice takes patience and persistence to master."
So true! Sounds so simple, but when you are used to mixing colors on a palette - building thin layers of paint instead to get to those colors is a bit daunting. And keeping the glaze thin enough and the waiting - oh the waiting for the layer to dry!