The 42x18mm Bullnose MDF keeps things fairly compact. At 42mm across, it works nicely where you don’t have much room for a wide trim, while the 18mm thickness gives it enough depth to stand away from the wall. What changes the look is the bullnose edge. Instead of a sharp, square finish, you get a softer rounded detail that’s easy on the eye once painted. This size is worth considering around smaller doors, windows or other indoor areas that need a tidy finishing piece. If you’re replacing old mouldings, measure them first. A few millimetres can make quite a difference at the joins.
