1548 Empress Isabel by Titian (Prado) coiffure and ruff
Isabella of Portugal's coiffure and ruff from Titian's 1548 portrait at the Museo Nacional del Prado. Excerpted from the Prado original (the previous image) by gogm.
Museo Nacional del Prado operates a wonderful Web site where you can download very high resolution images of works in their possession. This portrait is here. The only problem is they watermark their images, as can be seen here.
To search their site, go here and find the open box next to "BUSCAR" at the upper right quadrant. Key in the author or title and click BUSCAR. You will see "Resultado general de la búsqueda" listing "Contentos generales," "enciclopedia," and "obras." Click on "obras" to go straight to the works. Works are listed both in both English and en español.