Seurat tried to create contrast not only within the painting itself, but also between the canvas and its frame. He added borders in one of two ways: by painting an extension of the painting onto a wood frame or by actually stretching the canvas to allow for an extra few inches of room in which to paint the border. While many artists, like Edgar Degas, were obsessed with the framing of their works, few actually painted their own like Seurat. He desired to enhance his paintings past their original face value. It is a common disbelief that he painted continuously from the canvas to the frame in the same sitting, or even while they were attached. Instead, he usually displayed the work for a while and then would return back to the piece years later to add finishing touches in the form of a frame.
In the case of La Grande Jatte, Seurat exhibited the completed painting in 1885, but managed to return four years later in 1889 to add a border. 
This time, he stretched the canvas two to three inches on each side of the two by three meter painting. These borders were clearly intended to offer a contrast to the landscape in the painting itself, using the simple rules of color theory dictated by Chevreul and Rood. In this one case, Seurat came close to achieving sucess using complementary colors. Opposite the green grass, he painted with more of a reddish hue, while he bordered the blue sky with orange dots. He still did not fully succeed the ideal balance between colors because he incorporated more colors than were neccessary. However, such an advancement shows that he better understood color theory later in his career.