A big difference between the flamenco and classical guitar lies in the tocabilidad (action and playability of the strings). The action on the fingerboard is not as low as it used to be because many guitarists often play concertante and dislike the rattling and beating of the strings against the frets. What is much more important is the height of the bridge, or rather the space between the strings and the soundboard. Many guitarists measure this space with a cigarette. If it falls between the soundboard, the strings are too far apart. Others are of the opinion that the guitar no longer functions exclusively as an accompanying instrument. They require more space between the strings and the soundboard; after all, it is impossible to play concertante with a low action because the fingernails often touch the soundboard. Today, instruments with a low action at the bridge are only built at special request.
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Flamenco guitar: playability
Source: Flamenco Guitar Method by Graf-Martinez.