Gloss paint sheen has a highly reflective and shiny finish that is very durable and easy to clean, making it ideal for surfaces that experience heavy wear and tear. Semi-gloss paint sheen, on the other hand, has a slightly less shiny finish that is still durable and easy to clean, but offers a more subtle appearance. Semi-gloss is a popular choice for walls, trim, and cabinets because it strikes a balance between durability and aesthetics. Ultimately, the choice between gloss and semi-gloss comes down to personal preference and the specific needs of your project.