This means that a person must remove everything covering the body parts he washes during ablution that would prevent water from reaching his skin. This applies to those who work with paint. If this substance sticks hard onto the body parts they wash during ablution to the point that water cannot reach the skin, one is obligated to take it off by using paint remover before performing ablution.
This also applies to nail polish, which women put on their nails. They must remove this from their nails before performing ablution. A Muslim woman must remove this nail polish whenever she intends to perform ablution or ritual bathing, i.e. ghusl from sexual impurity. She may use this nail polish in her home afterward depending on whether she agrees with her husband that it is a means of beautification and adornment.
Taken from the book “An Explanation of ‘The Conditions, Pillars and Requirements of Prayer” Published by al-Ibaanah – Explained by Shaykh Muhammad Amaan al-Jaami (rahimahullaah) and Shaykh Abdul Muhsin al-Abbaad (hafidhahullaah)