Maybe this is nothing more than what Justice Potter Stewart said about pornography ("I know it when I see it!"), but when makers designate an instrument as "Student" rather than "Professional" grade, what factors are taken into account? What different things might this distinction entail when one is considering laminated, hybrid, and carved instruments? What, precisely, does this difference ultimately amount to? And just to be clear about what motivates the question, I just sold off a "student" level bass (Engelhardt EM1) owned for 20 years, and part of me thinks (rightly or wrongly) that I've earned the right to step up to a "professional" upright bass. BONUS QUESTION: how many "professionals" on this board regularly sport a "student" level instrument?