Why Do Brow Lamination & Lash Lift Processing Times Vary Between Clients?

Have you ever wondered why one client’s brows are perfectly processed in six minutes, while another client’s still feel resistant at eight? Or why the same lash lifting system can process incredibly quickly on one client but require considerably longer on another?

The answer is simple: no two clients have the same hair type.

Processing times should never be viewed as completely universal. Hair thickness, resistance, porosity, condition and previous chemical treatments can all influence how quickly Step 1 can effectively penetrate and restructure the hair. Understanding these differences is one of the most important skills you can develop as a brow or lash artist.

What Is Happening During Step 1?

During brow lamination and lash lifting, Step 1 contains a reducing agent that alters the disulphide bonds within the hair’s keratin structure. As reduction takes place, the hair gradually becomes softer, more flexible and easier to manipulate, allowing us to redirect it into a new position. But before the reducing agent can effectively act within the hair, the formula needs to gain sufficient access through the hair’s outer structure. This is where hair type makes a huge difference.

Haarlagen

Let’s dive deep into the layers of the hair: the cuticle, the cortex and the medulla.

De nagelriem

The cuticle is the hair’s outer protective layer and is composed of overlapping cells similar to fish scales, but they face downwards. A healthy cuticle is smooth and flat. This gives the hair its shine and protects the inner layers from damage. It also minimises the movement of moisture in and out of the underlying cortex, thus maintaining the hair’s hydration balance and flexibility. However, chemical processes and weathering can lift the cuticle and disrupt this balance, causing the hair to become dry and brittle and less able to protect the inner layers. When the scales are flat, and the cuticle is therefore smooth and sealed, the hair will retain good hydration, and moisturising properties cannot leak through the scales.

When the scales are raised and not flat, the hair will not retain good hydration as any moisturising agents will leak and escape. We can flatten raised scales to smooth the cuticle by maintaining the correct pH level. The cuticle itself is made up of 4–12 layers. The more layers present, the wider the diameter of the hair will be and will therefore be defined as a coarse hair type. The more layers present, the longer it will take for any product to penetrate through to the cortex, which is where we want to reach as an eyebrow maintenance artist. A healthy cuticle is crucial in order to maintain the overall good health of the hair.

De Cortex

The cortex forms the main bulk of the hair. It consists of long keratin filaments, which are held together by disulphide and hydrogen bonds. The health of the cortex depends largely on the integrity of the cuticle protecting it. The cortex is made up of 78–94% protein (keratin), 10–15% water, 3–6% amino acids and 1–3% melanin. Eyebrow hairs are mostly made up of tough, fibrous protein (keratin). As well as aiding strength, it is also responsible for giving the hair its structure, i.e. whether it is curly or straight. Keratin is particularly rich in cysteine (a sulphur-containing amino acid) which forms disulphide bonds between molecules, adding resistance and a rigid state. The amount of disulphide bonds will determine how curly or straight the hair is.

Keratin is made up of long-chain peptides (18–23 different amino acids) and smaller peptide chains (approximately two amino acids). Peptide chains are made up of amino acids. 18% of all amino acids in keratin are cysteine amino acids. Therefore, in order for a successful keratin structure to form, amino acids are key.

The cortex also houses melanocytes (melanin) which determine the colour of the hair. The colour depends on the amount, type and distribution of melanin within the cortex. You may see the hair becoming lighter in shade when performing brow lamination or lash lifting during Step 1, as this step is alkaline based. Melanin is very sensitive to an alkaline environment and can break down. However, this is not an indication to remove the product.

De medulla

The medulla is only present in coarser hair types and is the innermost layer of your hair. It consists of a soft, thin core of transparent cells and air spaces. We do not need to access the medulla.

Fine Hair

Fine brow and lash hairs generally feel soft, lightweight and easy to manipulate when brushed through. Because the hair is finer and may offer less resistance to the chemical process, Step 1 can often achieve the required level of reduction relatively quickly. This means fine hair may require a shorter processing time than stronger or more resistant hair. However, this also means you need to pay close attention throughout processing. Continuing to process fine hair simply because the maximum recommended time hasn’t been reached could unnecessarily compromise the hair.

Fine hair = typically faster processing and less room for unnecessary processing.

Normal Hair

Normal hair tends to sit somewhere in the middle. When brushing through the brows or lashes, the hairs may feel fairly strong with some natural resistance, without feeling particularly coarse or difficult to manipulate. The individual hairs will generally have a medium thickness and good flexibility. These clients are often straightforward candidates for brow lamination and lash lifting, but their hair should still be assessed throughout Step 1 rather than assuming a standard timing will always be appropriate.

Normal hair = moderate resistance and typically moderate processing.

Coarse Hair

Coarse brow or lash hairs generally feel thicker, stronger and considerably more resistant to movement. These hairs have a more robust outer structure and greater overall resistance, meaning it can take longer for Step 1 to achieve sufficient reduction within the hair. As a result, coarse hair will often require a longer processing time before it becomes soft and pliable enough to successfully restructure. This is particularly important when working with strong, downward-growing lashes or thick, stubborn brow hairs.

Removing Step 1 too early because you’re worried about overprocessing can leave the hair underprocessed, resulting in poor redirection or reduced longevity.

Coarse hair = greater resistance and typically slower processing.

Hair Type Isn’t the Only Factor

Although we often categorise hair as fine, normal or coarse, this should only form part of your assessment.

Two clients who both appear to have fine hair may still process very differently. You should also consider:

• The condition of the hair
• Previous brow lamination or lash lifting treatments
• Tinting and other chemical services
• Natural hair strength and elasticity
• The client’s natural growth direction
• The reducing system being used
• The specific formulation and strength of your product

Manufacturer Timings Are a Guideline

Manufacturer processing times are incredibly important. They give you the framework within which the product has been developed and tested. However, they aren’t a replacement for professional hair assessment. If a manufacturer provides a processing window, your job as a trained artist is to assess where your individual client sits within that window. A client with fine, responsive hair may be ready towards the shorter end, whereas strong, resistant hair may require longer. Rather than simply applying Step 1, starting your timer and removing the product when the clock tells you to, continually consider:

• How did this hair feel before I started?
• How does it feel now?
• Has the resistance changed?
• Is the hair becoming softer and more flexible?
• Can I redirect it more easily than I could before processing?

The timer provides the framework.

The hair provides the information.

Learn to Look for Changes in the Hair

Successful processing isn’t simply about reaching a particular number of minutes. You’re looking for a change in the behaviour of the hair. As Step 1 works, resistant hair should gradually become softer, more pliable and easier to manipulate. With brow lamination, you may notice that the hairs become easier to redirect and don’t spring back as strongly towards their original growth direction. With lash lifting, the lashes should gradually become more flexible and responsive, allowing them to accept the new direction and curvature required for the lift.

The aim is to achieve sufficient reduction without unnecessary structural compromise.

Don’t Become Scared of Processing

Fear of overprocessing can sometimes lead artists to consistently underprocess their clients. The answer isn’t to remove Step 1 as quickly as possible. Equally, poor results shouldn’t automatically be corrected by increasing everyone’s processing time. The goal is to understand what the individual hair requires.

Fine hair may need less. Coarse, resistant hair may need more. And normal hair may sit somewhere between the two.

Developing the ability to recognise these differences is what allows you to work confidently rather than treating every client with exactly the same timings.

Conclusie

There is no single processing time that will be perfect for every brow lamination or lash lift client because every client’s hair is different. Manufacturer timings provide an essential framework, but your professional assessment determines where your client sits within that framework. Assess the hair before you begin. Understand whether you’re working with fine, normal or coarse hair. Consider its condition, resistance and chemical history. Then continue observing how it responds throughout Step 1. The more treatments you perform, the more confident you’ll become at recognising the subtle changes in resistance, flexibility and movement that tell you how the hair is processing.

Don’t just learn your timings. Learn the hair type.