All our wood risers (from the Seneca Edition Zero onward) are precision-machined in South Africa from the luxurious Kiaat wood native to that country. These are then coated with Rubio Monocoat, which is a protective finish that, unlike many less natural varnishes, offers the decided advantage of allowing owner maintenance over time.
Boiled linseed oil (optionally blended with beeswax, as with this excelent polishing compound) can be buffed over scratches to cover and protect damage to the finish and maintain the wood over years of use.