how dyes effect the hair structure Flashcards
Which part of the hair structure does temporary colour pigments effect?
The colour pigments are too large to enter the hair so they coat the cuticle this is why they are washed away so easily
How could a temporary colour stain the hair?
If the hair is porous the molecules may be able to enter the cuticle and get trapped, causing staining
How does a semi-permanent colour effect the hair structure?
The semi colours have different sized colour molecules, the largest coat the cuticle while the smaller ones coat the inside of the cuticle and can penetrate a little way into the cortex.
How does porosity effect the way a semi colour washes out?
If the hair is porous in places, the colour will wash out quicker than the healthy parts of the hair creating patchy results.
How many shampoos does a semi-permanent colour last?
6- 8 washes
Does a quasi permanent colour use a developer?
Yes, although it is only a low developer such as a 3 - 10vol
How does a quasi effect the hair structure?
Because of the low developer the hair has a slight regrowth. The molecules slightly penetrate the cortex and stain the natural pigments with the artificial colour
How long does a quasi colour last?
A quasi lasts around 16 - 24 shampoos, it fades slightly each time as the molecules slowly seep out the cortex
The effect of permanent hair colour on the hair structure?
Permanent colour molecules are small and penetrate the cortex, The oxygen from the developer oxidises the permanent colour so that they expand and cannot escape the cortex .
How does bleach effect the hair structure?
Bleach products are mixed with hydrogen peroxide, which opens up the cuticle scales and penetrates the cortex where the natural pigment melanin is found. Once inside the natural pigment is oxidised to form a colourless oxymelanin
What is the difference between Eumelanin and Pheomelanin?
Eumelanin is the granular pigment and contains the black and brown pigment.
Pheomelanin is the diffuse pigments as they are smaller and harder to remove, it contains the red and yellow pigment.
what does the lightening curve show?
The lightening curve shows the stylist what tones will be exposed during the lightening process.
What do you use 10vol / 3% developer (hydrogen peroxide) for?
10vol is used to add weak tones/colour such as a bleach toner
what is 20vol / 6% developer used for?
20vol is used for adding colour (most tinting purposes)
what is 30vol / 9% developer used for?
30vol is used to lighten hair
