Volume eyelash extensions are multiple extensions applied to one natural lash. Volume lash extensions are customized to the individual look you are trying to achieve. A mixture of 2D, 3D, 4D, 5D and 6D are applied to the natural lash. Thickness is dependent on what weight the natural lash is able to hold without causing damage, as well as the style preference. MUST HAVE 1/3 OF EXTENSIONS TO BE CONSIDERED A FILL