What type of water-soluble substances is often used in nail polish ingredients to improve application?

Water-soluble substances play a crucial role in the formulation of nail polishes, particularly in enhancing their applicability and flexibility. Plasticisers are used in nail polish to improve the ease of application and to ensure that the polish adheres well to the nail surface while also allowing for some degree of flexibility. This flexibility helps prevent the polish from chipping or cracking during everyday activities, as it enables the polish to move slightly with the nail.

The role of plasticisers is essential in achieving a smooth and even finish, as they reduce the brittleness of the formulation, ensuring that the polish can withstand various stresses. This ultimately contributes to longer-lasting wear and a more aesthetically pleasing result.

Other substances, such as oils and waxes, may alter the consistency or finish of nail products, but they do not specifically enhance the application in the same way plasticisers do. Meanwhile, preservatives are primarily used to extend the shelf life of cosmetics by preventing microbial growth, rather than to improve the application process.