The earth paintings are painted on the ground on unstretched artist canvas and they do not dry square. I personally feel that they are best hung unframed. Nature is not framed.
I suggest using small nails. Sculpture the painting by allowing gentle hills and valleys to be created. The earth painting will encourage you to participate in its making by creating highlights and shadows. To get the sculptured effect nail the upper left corner to the wall. Next, take the right upper corner of the painting, but instead of having it totally stretched bring the corner back about four to six inches and attached this end. It does not have to be exactly parallel. Next, near the center put another nail. The painting starts to form itself and now you can adjust and sculpture the painting. You will want to place nails between the end and the center nail on the upper part of the painting. Next, go down the right side and place nails about 1/3 down and again a second another 1/3 down. Go to the left side and do the same. You will see where it is best to place the nails, where the painting wants to fold or rise.
Again, along the bottom of the painting place nails about 1/3 of the way in from each corner. Push up a little on the painting to give it more sculpture as you are putting the nails in. This helps create the hills and valleys, and since the painting’s texture is stiffened with the earth it holds the shape. You can push in on the painting where every nail is attached if you desire lots of hills and valleys or you can keep the edges straighter.
I build a frame smaller than the painting. Then I nail the painting to the frame, allowing the painting to overlap the edges by about 3 inches while creating the desired hills and valleys. The painting is more rectangle than free flowing but it still has the effect of floating on the wall since one does not see a frame.
Another hanging style on smaller paintings is to nail the painting to the top of a piece of driftwood, or other appropriate wood. This allows the painting to flow down, away from the wall.
Many people who have purchased an earth painting were going to frame it, but after being on their walls they realized it did not need a frame. Nature is not framed. The earth paintings have a leathered texture when dry. The soil soaks into the artist quality canvas.