What substance is primarily responsible for giving gel enhancements their shine?

The substance primarily responsible for giving gel enhancements their shine is nitrocellulose. Nitrocellulose is a film-forming agent that, when applied, creates a smooth surface that reflects light, resulting in a glossy finish. The shine produced by nitrocellulose is a key characteristic of many nail products, particularly in the context of gel enhancements.

While acrylates, polyester resins, and silicones play various roles in nail products and can contribute to the overall durability and flexibility of gels, they do not specifically provide the luster that is iconic to gel finishes. Acrylates are generally involved in creating the structure of acrylic nails, polyester resins are used in some gel formulations for their strength and bonding properties, and silicones can enhance smoothness but are not primarily responsible for shine. Therefore, nitrocellulose stands out as the main element that imparts the desirable glossy appearance to gel enhancements.