Ok here’s the complicated scientific explaination on sheen; its how shinny the paint is. There you have it folks. The levels of sheen from least to greatest are flat, eggshell, satin, semi-gloss, and gloss. Flats are also called matte, or velvette. Eggshell can also be called low-luster, and every once in a while you will see a manufaturer label something “high gloss”. Every manufacture has a different standard of how much “shine” is necessary for a certain name. The best thing to do is get a sample of the paint and put it on the wall so you can see for yourself.