TonerQ: I purchased some blonde toner to fix my yellowy hair problem and I've never used toner before. So, how often is it O.K. to use it, or does it not matter? This service is great by the way, keep the good work up!
A: If the "toner" you selected was a "professional grade" toner formula (one that is combined with a developer product before application) then one application should be sufficient to counter the yellowing. The idea of a "toner" can be misleading:
Hair color applications can be categorized into two basic types - one and two-step color processes. Darkening the hair is generally a one-step (or single-process) color service. Lightening the hair a slight amount can be accomplished in a one-step (single-process) color service, but dramatic lightening requires a two-step (dual-process) color service.
The two-step color service includes a lightening step, followed by a color (or toner) step. The term "toner" generally refers to a lighter, more translucent color that is used to temper an existing color, and is most often used with strongly lightened hair to remove brassiness. (Toners are also used to warm up and remove mousiness from brown hair shades.)
Toner, however often uses a developer of its own, and therefore has a chemical effect on the hair. Because of this, the toner should be used no more than needed to correct the issue at hand. Use the toner formula as directed in the instructions. If the yellowing is not sufficiently countered by the toner, then you may make a second application provided your hair is in good condition.
Remember that the hair's condition is your main concern and determiner over whether most chemical services are safe to perform. There's no point in toning the hair to remove yellowing if the process is going to mean the hair is damaged to the point of no repair.
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