Above are two of the 4,600 pieces of high resolution artwork available for download right now, part of The Getty museum's free Open Content Program. Alongside the pair of Jan van Huysum floral still lifes, Titian, Renoir, Cézanne, Gauguin and countless other famous artists' works are available to use for both commercial and non-commercial purposes...
Visitors to the Getty Search Gateway's Open Content Images can browse through the growing collection of 4,600 images, and further filter their search according to parameters such as art type (e.g. painting, drawing, manuscript, sculpture, etc), topics, by artist, and by location portrayed.
Upon downloading, you'll only be asked whether you're downloading the image for personal or professional use, and whether the image is being used by a private individual, non-profit, or for-profit organization (The Getty is gathering information about who and how their collection is being used to better fine tune future offerings).
I downloaded a digital copy of Pietro Paolini's painting, Achilles among the Daughters of Lycomedes, and found the transfer fast; the total file size was 22.7 MB jpeg at 4,885 x 2824 resolution once opened, a resolution fine enough to print out using a capable archival quality inkjet printer for printing on art stock or inkjet compatible canvas for framing (with an appropriate higher end printer model, which rule out most consumer grade budget models).
Tip: Take your chosen file(s) over to Kinko's and use one of their large format printers and you've got an instant wall-sized reproduction piece for about $47 (just grayscale though).
(Images: The J. Paul Getty Museum)