cjs33139 this is a classic gray area. The most accurate title to put on this position is furniture designer. You could custom design a wood side chair for a specific interior and build one for the CEO’s office. Six months later they want 3 dozen to furnish the confrence rooms too. (36 chairs is mass production albeit a very small run) A year later you may have the chair in full production. Only then would you go back and reclassify your past design efforts as ID?