KD is a boutique instrument workshop founded in 1997 by Bulgarian luthier Kostadin Dimitrov, who hand-builds a small number of electric guitars and basses each year from his shop in Bulgaria. The operation is run by Dimitrov together with his wife, Silvia Nikolova, who handles the marketing and design side; one of the shop's signature models, the Silvia, is named after her.

The brand is known for its focus on rare local tonewoods, particularly Balkan Maple that is naturally air-dried for around seven years, and for contemporary body shapes that depart from traditional templates. Output is limited to roughly ten to twenty instruments per year, placing KD in the small-batch, custom-luthier tier alongside other European boutique builders rather than production brands.