Glazing is an acrylic painting technique that involves layering transparent colors to blend colors and add depth. It produces rich, jewel-like surfaces. The document discusses how glazing involves applying a transparent color layer, letting it dry, then applying another transparent layer on top to blend the colors visually rather than physically mixing on the palette. It also provides tips on mixing glazes with palette knives rather than brushes, applying successive layers and allowing proper drying time between layers to achieve transparency and depth.