The differences between permanent, demi-permanent and semi-permanent hair color
PERMANENT HAIR COLOR
First, let’s quickly cover how permanent hair colours work. They’re usually formulated with ammonia, which helps to open up the hair cuticle scale so that the pigment can penetrate deep within the hair shaft. It’s this process that makes permanent hues so intense and can help them last longer than any other colour. Permanent hair colors are able to give your client up to 100 % Gray coverage.
DEMI PERMANENT HAIR COLOR
Demi-permanent hair colours work quite differently. They tend to be ammonia-free, yet they feature an alkali ingredient that gently opens just the outer/ cuticle layer of the hair shaft, so that the colour molecules can penetrate. Because this hair colouring process isn’t as intensive as permanent color. Demi-permanent colours don’t last as long as permanent shades. However, they are also more gentle to your hair, and offer softer regrowth or line of demarcation in between colour appointments. Demi permanent hair colours offer up to 70% grey coverage. On average a demi-permanent shade will last around 24 washes, but it may stay true even longer if they’re working bold shades and/or you’re using professional hair care products at home. A demi-permanent colour is the perfect pick for anyone who wants to transform their shade, get rid of brassy or yellow tones or to enhance an existing colour. This ultra versatile option is also a great choice for a root smudge.
SEMI PERMANENT HAIR COLOR
Semi-permanent shades only coat the surface of your hair strands. They do not open up the cuticle scale and pigment is not deposited inside. Semi-permanent hair colors only stain the hair shaft. Semi-permanent hair colour may not last as long as a demi-permanent hue, although it can still offer plenty of staying power depending on the hair base you’re working with and its porosity.
Semi-permanent shades last around 10-20 washes, however, if the hair is slightly porous or light in colour then the pigment will last much longer.
Semi-permanent colors offer a low-commitment fling with a new shade, or simply to enhance or correct an existing hue without the risk of any damage at all because it only tints the surface of the hair strand, not the inside – it has no effect on the internal structure and condition of the hair. These shades might not last as long as a demi-permanent or permanent hue, their zero damage finish means you can top them up as often as you like.
WHAT’S THE VERDICT?
THE DIFFERENCES BETWEEN DEMI-PERMANENT AND SEMI-PERMANENT HAIR COLOURS
Now for a quick refresher. Let’s look at exactly what makes demi-permanent and semi-permanent shades different, so you can make the right colour product choice for your client’s hair goals. Here’s what you need to know…
Longevity: Demi-permanent hair colours, on average, last for up to 24 washes, while semi-permanent shades last for around 10-20 washes. In both cases, this may be longer if the hair is porous or very light, or the shade you’re applying is bold.
Colour process: Semi-permanent hair colours deposit on the surface of strands, while demi-permanent colours do the same, they also gently open the cuticle layer of the hair to deposit a small amount of pigment inside.
Lifting: While semi-permanent hair colour isn’t designed for lifting locks, mixing demi-permanent colour with the right developer lets you very subtly lighten your client’s hair. This makes it ideal for creating vibrant reds, for example, or bumping up a base colour
Grey blending: If a touch of grey blending is important, use a demi-permanent colour over a semi-permanent. And if it’s full coverage they want, a permanent colour is the best choice.
Condition: Semi-permanent hair colours are all damage-free, while demi-permanent hair colours are low to no damage.