1-phase gel or 3-phase system – almost everyone who starts with gel nails or reorganises their salon range faces this question. Both systems give you strong, glossy gel nails, but they differ in structure, working speed and how flexible you are. Here you'll learn what the terms mean, what the pros and cons are and which system suits you.

What does “phase” mean for gel nails?

A “phase” is the working step a gel takes on during the nail modelling. Classically, there are three tasks:

• Base (adhesion): bonds the prepared natural nail or tip to the following layers.
• Build (modelling): gives the nail shape, strength and the right stress zone.
• Seal (finish): completes the modelling and adds shine.

With a 3-phase system you use a separate, specialised gel for each task. A 1-phase gel (also called single-phase or all-in-one gel) handles all three steps with just one product.

What is a 1-phase gel?

A 1-phase gel is used as base, builder and sealing gel. So you work from just one jar – that saves time, space on your desk and product changes. A typical routine: thin adhesion layer, cure, build layer, cure, possibly a thin finish layer, cure, remove the sticky layer.

At BNC you'll find 1-phase gels in different consistencies:

• BNC Profi Gel – our bestseller: self-levelling no-file gel, medium viscosity with excellent adhesion and clear coverage; for beginners, advanced users and pros.
• BNC Studioline 1-Phase Gel clear – medium viscosity and self-levelling, develops only little heat when curing; also suitable as a finish.
• BNC All in One Builder 1-Phase Gel rose No. 1 – thick, stable and self-levelling with a rosé coverage; also for form extensions.
• BNC 1-Phase Gel Elasto Rosa No. 2 – high viscosity and thixotropic, easy to pinch; pink in the jar, cures transparent and is vegan.

You'll find all other variants in the 1-phase gels category.

What is a 3-phase system?

With a 3-phase system you combine three gels, each specialised for its task:

1. Adhesion gel / base gel: low viscosity, applied very thinly. For example the BNC Masterline UV/LED Base Adhesion Gel clear or the HEMA-free BNC Adhesion Gel violet. More choice: base gels.
2. Builder gel: thick for shape and strength, such as the self-levelling BNC Builder Gel clear rose, which is also suitable for refills and form extensions. Find more under builder gels.
3. Finish / sealing gel: low to medium viscosity for shine and protection, e.g. the BNC Masterline UV/LED Sealing Gel clear or the HEMA-free BNC Finish Gel High Gloss without sticky layer, for which you don't need a cleanser. All variants: finish gels.

How to find the right builder gel is explained in detail in our article Builder gels compared.

1-phase gel vs. 3-phase system: direct comparison

Which system is right for whom?

A 1-phase gel is ideal if …

• you do your own gel nails at home and want to start with just a few products,
• you want to do a quick natural nail overlay or refill,
• your nails adhere well and don't cause any particular problems,
• you want to save time per client in the salon.

A 3-phase system is ideal if …

• you model long extensions or demanding shapes,
• clients tend to have lifting and you want to choose the adhesion layer specifically,
• you want to control finish and shine independently of the build,
• you work with make-up, colour or effect gels between build and finish.

By the way, many pros combine both: a 1-phase gel for standard refills and a separate adhesion or finish gel for difficult nails.

Application step by step

With 1-phase gel

1. Prepare the nail: push back the cuticle, remove the shine, remove dust and dehydrate. You'll find tips in The perfect base for gel nails.
2. Apply a thin adhesion layer and cure.
3. Model the build layer, set the stress zone and cure.
4. File into shape if needed, apply a thin finish layer and cure.
5. Remove the sticky layer with cleanser.

With a 3-phase system

1. Prepare the nail in the same way.
2. Apply the adhesion gel very thinly and cure.
3. Model the builder gel and cure – for long nails ideally in two layers.
4. File into shape, remove dust, optionally apply colour gel.
5. Apply the finish gel, cure and – depending on the product – remove the sticky layer.

The exact curing times are given in each product description. For curing you can use, for example, the BNC UV/LED lamp with 26 watts, which according to its description cures all LED and UV gels. Read more about the finish in our guide to sealing gel. Terms like “thixotropic” or “sticky layer” are explained in our nail design glossary.

FAQ: 1-phase gel and 3-phase system

Can you use a 1-phase gel without adhesion gel?

Yes, that's exactly what it's made for: a 1-phase gel acts as its own base. An additional adhesion gel can still make sense if nails tend to lift.

Does a 3-phase system last longer?

Not automatically. Durability depends mainly on clean preparation, thin layers and complete curing. However, the 3-phase system gives you more options to adapt each layer to the nail.

Which system is better for beginners?

To get started, a 1-phase gel is usually easier because you only have to learn one product and one routine. As you gain confidence, you can add individual specialist gels.

Can I mix 1-phase gel and 3-phase gels?

Yes, many people combine, for example, a separate adhesion gel with a 1-phase gel or seal with a dedicated finish gel. What matters is that all products cure with your lamp.

Can I also extend nails with 1-phase gel?

That depends on the consistency. According to its description, thick, stable 1-phase gels like the BNC All in One Builder 1-Phase Gel rose No. 1 are also suitable for form extensions.