Dulux Eggshell Once Oil Based

Hi there, What you are experiencing is a classic case of "flashing" (uneven sheen or gloss variance). Painting white over white makes it very easy to miss spots, but the root cause usually comes down to how the surface was prepared and how the paint is drying.Here are the most likely reasons this happened:Uneven Porosity (No Primer): Bare or aged wood has uneven absorption levels. Areas around knots or worn patches suck up the paint quickly, leaving a flat, matt finish. The less porous areas keep the paint on the surface, causing it to look shiny.Trapped Moisture: Because this is directly above bathroom tiles, the wood may have absorbed moisture or steam before you started painting. As that trapped moisture tries to escape, it ruins the paint’s ability to cure evenly.Contaminants on the Surface: Bathrooms are prone to invisible build-ups of soap scum, cleaning chemicals, or silicone residue right above the tile line. If the wood wasn't thoroughly degreased, the paint won't adhere properly, altering the finish.Uneven Coat Thickness: It is incredibly difficult to see where you have applied paint heavily or lightly when doing white-on-white. Thicker patches will dry slower and often retain a higher sheen than thin patches.