What is the main reason for holding the e-file flat and parallel to the nail?

Holding the e-file flat and parallel to the nail primarily reduces friction and helps avoid burns, which is crucial during nail enhancement procedures. When the e-file is positioned correctly, it maintains an optimal angle that prevents excessive pressure on the nail and minimizes the risk of heat buildup. High friction can lead to overheating, causing discomfort or even injury to the client. This technique enhances safety and comfort while ensuring the filing process is effective.

The other options, while they may contribute to the overall approach to using an e-file, are not the primary reason for maintaining a flat and parallel position. Ensuring an even surface and improving visibility are important, but they do not directly address the immediate concerns regarding heat and friction that can lead to burns. Likewise, while filing speed can be an advantage of proper technique, it is not the main consideration when discussing the angle of the e-file in relation to safety and client comfort.