Hair glaze is a non-permanent colour that does not penetrate the hair shaft but coats the outside of the hair and adds shine. Hair toner also coats the hair shaft, but its purpose is to change the shade of the hair. Toner can also add some shine, but its primary function is to neutralise unwanted tones such as brassiness or yellow hair.
Toning Colored Hair
Lightening your hair, especially by more than two shades, increases the chance of leaving a brassy or yellowish tone. A hair toner with blue or violet tones used after the lightening process "tones down" the brassy colour. Salon stylists usually apply toning in the sink after the lightening or colouring process.
Toning Natural Color
Even without colouring, hair can develop a brassy or yellow tone. This can be the result of hard water in the shower, chlorine, sun or hair products. Toner can return hair to its more natural colour.
How Does Toner Work
On a colour wheel, blue and violet are on the opposite end of the spectrum from orange and yellow. Depositing a blue or violet colour onto brassy hair will neutralise the colour.
When to Use a Glaze
Both natural and coloured hair can become dull and flat over time because of product use, health issues and environmental factors. Putting a glaze on the hair shaft adds a non-permanent colour that reflects light.
How Does a Glaze Work
A glaze sits on the outside of the hair cuticle and provides a reflective sheen. Glazes are available without colour, or with colour to give your hair a "refreshed" look.
To Salon or Not to Salon
Toners and glazes do not last more than a few weeks. Toners and glazes are pretty inexpensive in both the salon and the store, As of 2009, costs range from £6 in the store to £32 in the salon. Toners are also present in shampoos and conditioners that are made specifically for your hair colour.