The Dutch portrait painter referred to in the crossword solutions is Frans Hals (4 letters) and Rembrandt (9 letters). Frans Hals was a Dutch Golden Age painter who lived from 1582 to 1666. He is best known for his loose painterly brushwork, which helped to create a sense of movement in his portraits. Rembrandt van Rijn was a Dutch painter and printmaker who lived from 1606 to 1669. He is considered one of the greatest painters in European art history and the most important in Dutch history. His works are renowned for their mastery of light and shadow, and his ability to capture emotion in his portraits.