What do 1D, 2D, 3D, 5D, and 8D mean?

D stands for the number of extensions per natural eyelash. The higher the number, the fuller the look—provided the extensions are fine enough not to exceed the natural weight.

• 1D (Classic, 1:1): One extension per natural eyelash—natural and defined.
• 2D–3D (light volume): Two to three ultra-fine extensions per natural lash—more density with a natural finish.
• 5D–8D (heavy volume/mega volume): Five to eight very fine extensions—maximum, glamorous effect.

1:1, Volume & Hybrid—when should I use which technique?

1:1 (Classic): For clients who prefer a subtle, natural result.

Volume (XD): More fullness thanks to fans with multiple fine extensions—ideal for dense, even looks.

Hybrid: A combination of 1:1 and Volume—modern, textured, and highly customizable.

Wide vs. Narrow Fans

• Wide fans (fluffy): Look soft and airy, visually distributing the density.
• Narrow fans (dense): Create a more pronounced, denser base—ideal for “eyeliner-like” effects.

Practical Tip & Tool

The selection of diameter and D-number must be based on the thickness of the natural lashes. Use our weight chart or the CFB Lash Extension Guide (Custom GPT) , to avoid overloading.

• Length rule: The optimal extension should be no more than 1/3 longer than the natural lash.
• Weight rule: If the extension is heavier than the natural eyelash, it is not suitable for that eyelash.