All my boxes are finished with a mirror smooth lacquer or urethane varnish finish, both of which are durable and resistant to water and other stains. 

Whereas other craftsmen use oil finishes which leave wood pores open to collect dirt, which are nearly impossible to clean, my boxes can be cleaned with ordinary household cleaners.

I recommend either window cleaners such as Windex, or dishwashing detergent, but not petroleum based cleaners such as Fantastic or 409.

If for any reason the finish becomes damages, repairs are fairly easy and can be accomplished by most furniture repair shops.