Which portion of the brush is used to press and smooth acrylic product at the free edge of the nail?

The middle portion of the brush is specifically designed for pressing and smoothing acrylic product at the free edge of the nail. This part of the brush provides the optimal control and flatness needed to meld the product seamlessly along the edges, ensuring a neat and professional finish.

Using the middle section allows the nail technician to apply adequate pressure while maintaining precision, which is essential for achieving a smooth and even application. The flexibility of the bristles in this area also makes it easier to manipulate the acrylic without risking the integrity of the nail enhancement.

In contrast, the end portion would typically be used for more detailed work or for fine-tuning, while the top portion might be more suited for application and spreading the product rather than smoothing it at the free edge. The sides of the brush could assist in creating side walls or for detailed shaping, but they would not provide the same level of effective contact needed for uniform smoothing along the free edge as the middle portion does.