Glazing is how painters get colour that seems to glow from inside. Instead of mixing the exact colour and painting it on once, you lay thin, see-through layers of paint over a finished underpainting, one on top of another. Matt Fussell of The Virtual Instructor shows the whole process on a slice of cherry cheesecake, from a grey underpainting to glossy red topping.
How to glaze with acrylics: the short version
- Paint the whole picture in greys first, with a full range of darks and lights.
- Thin your colour with glazing medium and a little water until it is see-through.
- Brush the glaze on with a soft brush and let it dry completely.
- Add more glazes until the colour is as strong as you want.
- Finish with thick white highlights on top.
Why paint in grey first?
This is called indirect painting, and it is the old masters' way of working. The grey stage is called a grisaille. It lets you sort out light and shadow without worrying about colour at the same time. Get the values right and the colour almost takes care of itself, because every glaze lets the light and dark underneath show through.
Grey is not the only choice. A blue underpainting gives the finished piece a cooler feel, and one in browns such as raw umber warms it up.
Glazing medium, matte medium or water?
You do not need glazing medium to glaze. Matt points out that matte medium or even water alone will work. Medium is the safer bet, though. Too much water breaks down the acrylic binder, and the paint can stop sticking to the canvas or lift off in patches. Medium thins the colour while keeping the paint film strong. It also slows drying a little, which gives you more time to brush it out.
Brushes and drying time
Use soft synthetic brushes for glazes. Stiff hog hair brushes leave streaks that show through every layer. A flat or bright brush covers large areas, and a small round handles details like the stem.
Acrylics dry fast, which is good news for glazing. You can stack layers in one sitting. The one rule is to let each glaze dry right through before the next. Brush over a damp glaze and you will pull the pigment back off.
Good colours for glazing
Transparent pigments glaze best. Alizarin crimson, Indian yellow, Phthalo blue and Viridian are all good. Opaque colours like cadmiums can still glaze when thinned well, but they cloud faster. Thin white is useful for knocking back a colour that has gone too strong, as Matt does with the yellow plate.
Glazing builds on a few basics. If you are new to acrylics, start with acrylic painting for beginners, then read how to thin acrylic paint. Glazes are also a gentle way to fake soft transitions, which pairs well with blending acrylic paint and mixing acrylic colours.
Common mistakes
- One thick glaze. Several thin layers look richer and are easier to control.
- Weak values. A pale underpainting gives a flat result. Push the darks.
- Glazing too soon. Wait until the layer below is fully dry.
