Here are my experiences and opinions....
French polish is easily damaged with the slightest touch of a fingernail. A nice finish for a classical IMO, but not tough enough for a hard played flamenco. I cannot tell any improvement in tone for flamenco comparing two fairly identical guitars, one French polish and the other lacquer. A fine classical might have a tonal difference, but the main reason FP is used over lacquer is cosmetic beauty. FP is easier to repair than lacquer if the damage is just the finish. Lacquer is more durable and easy to clean and looks good enough on a flamenco. Hand rubbed varnish is both durable and beautiful and has excellent tonal qualities, but the labor and time involved is not worth it. I think that FP was so popular in the past on expensive fine guitars as many individual Spanish guitar makers did not have any room or equipment for spraying lacquer and applying it by hand is more difficult than applying varnish. Lacquer is my choice on a flamenco. What is your preference?
