CREATE TABLE table_10557 ("Year" FLOAT, "Butterfly" TEXT, "Artist" TEXT, "Mintage" FLOAT, "Issue Price" TEXT, "Finish" TEXT)

Which artist's work is the butterfly Tiger Swallowtail?
SELECT "Artist" FROM table_10557 WHERE "Butterfly" = 'tiger swallowtail'
SELECT "Artist" FROM "table_10557" WHERE "Butterfly" = 'tiger swallowtail'