A vertical member between the top and bottom rails.  When a baluster is turned on a lathe, it is often called a spindle, and is what most of our customers are looking for on their porch or deck.  Sawn balusters a board with decorative scrollwork.  Balusters can be made of just about any material, but for porch and deck railing, we prefer authentic high quality wood of a species appropriate for exterior use, or High Density Polyurethane (HDP) for a synthetic alternative.