I got to the NGA yesterday just before it opened, and was set up and ready to paint by 10:30. I started the day by examining the original closely, and took several close-up photos of different areas. I don't know how well they convey on the computer, but take a look at Redfield's thick paint and brushwork:
(click the images for a larger view)
Redfield's paint is thick and luscious. If you look closely at the wooded area, it looks like he painted the general shape of the woods, slathered the sky color and snow color on top, and then carved out the tree shapes, exposing the underpainting, and then painting the trees in also. (Back and forth.) But I know that he did this painting in one 7-hour session, so the underpainting would have still been wet. I also know (because it tells you on the NGA website) that it was so cold that his paint was frozen, and he had to use copious amounts of oil to get it to be malleable. My conditions in a room-temperature environment are of course different, so I don't know if I could duplicate his surface (even if I was skilled enough), but I'm trying.
I decided to start painting on the sky and work my way down. I purposely did NOT work on the bottom of the painting, because I didn't want the bottom edge to be wet. I don't want to take the chance of getting paint on the National Gallery's wood floors when I set the painting down, which I invariably have to do at some point. So I just concentrated on the top half of the painting today.
Well, I really didn't get very far. I got a lot of paint onto the sky area, but kept feeling like my sky is too dark. But when I lightened it up with more white, it still didn't look as bright and luminous as his. I also started to work on the woods, bringing sky color down between the trees. A lot harder than I thought it would be. I kept running out of my mixed piles of paint, mixed more, used it up in a few brush strokes, and never could build up any kind of thickness. I worked until noon, and took a long lunch (which also included a trip to the library in the East Wing to look at a book.)
After lunch I worked a bit more, and wrapped up around 3. Maybe next time I'll get bolder about using more paint. I think a trip to the art supply store is in order.