Glazing methods you need to know includes understanding the difference between transparent and semi-opaque paint. Transparent paint is like stained glass or coloured cellophane. Semi-opaque is like a ‘fog’ of colour. Glazing means to lay down a layer of colour which has been thinned with medium. This can be done on white, another transparent colour or on an opaque colour. Colour glazes are like layers of stained glass when mixing colours for your paintings.

For oil painters, more time is needed for paint to dry. Drying can take days or weeks. Acrylics dry in minutes. Oils have better transparency and longer working time. 

Glazing methods you need to know:

• Glaze on top of dry paint.
• Use transparent paints. To check, refer to manufacturers pigment lists, or test paints on black.
• Thin acrylic paint with a mixture of 1 part glazing medium and 2 parts acrylic gloss polymer medium.
• Glazing medium is a retarder. Too much creates a sticky mess of paint that might lift.
• To create semi-opaque glazes that are mist-like, add zinc white to paints. Or use semi-opaque or opaque paints diluted with the glazing/medium mixture.
• Test which colour to place on top. For example try blue on top of yellow to make green or vice versa. 
• Test also whether to add a transparent layer over a tinted or other transparent colour. It all depends on the effect you want.
• Decide if you want a bright or duller colour.
• For each glaze, the value darkens. For this reason you need to plan ahead. Otherwise your painting will be too dark.
• Try to glaze in a logical order. Paint a majority of areas to be glazed with yellow for instance. There will be areas to later glaze with yellow, or red or blue, such as the smaller details.

PS I am grateful to Canadian artist David Langevin for providing us with invaluable insights (especially on glazing techniques) during his Mastering Acrylics workshops — as well as his Mastering Oils Workshops. Check out his work and technical Q&As at http://davidlangevin.com.  Thanks David!