Painting a deck railing is much more difficult than staining or sealing it.

Painting will also increase the maintenance time and labor required to have the paint continue to look good over the years. No matter how well the primer and base coats are applied, painted wood surfaces left exposed to the outside elements tend to peel and chip. Because of this, prep-work (scraping and sanding) of the railing to paint again becomes more difficult over time.

Water-stains, mildew, dirt etc. become much more prevalent on painted surfaces, the railing will most likely need to be cleaned more often. Some stains like berries and mildew may even penetrate the top layers of paint making them difficult if not impossible to remove.

Paint may exaggerate wood blemishes and rough mill cuts it also hides the natural beauty and texture of the wood grain.