Studios that openly demonstrate technique and quote per-piece pricing based on detail level are legitimate; be specifically wary of shops immediately flanking the City Palace entrance that quote flat 'this is a museum piece' prices with no demonstration - that's the classic tourist-trap setup here.
Udaipur was home to the Mewar school of miniature painting, which flourished from the 17th century under royal patronage of the Sisodia rulers after the capital moved there in 1615, with master artist Sahibdin producing celebrated illustrated manuscripts under Maharana Jagat Singh I. Distinct from Mughal-influenced Rajput schools, Mewar painting retained an independent visual style reflecting the dynasty's long resistance to Mughal rule, using natural pigments ground from minerals, plant matter, and precious metals. The tradition declined as court patronage faded and photography supplanted portrait painting, but small family-run studios in the old city near Jagdish Temple continue the technique today, and original Mewar-school works are held in the City Palace Museum and Rajasthan's Government Museum.