Bottom-Weighting and the Golden Mean

When framing artwork with mat board, one of the typical questions is about mat border size. Specifically, how wide should the borders of the mat board be? Framers, artists and art lovers all have different opinions. Some like single mat boards with four equal borders, while others love the look of double or even triple mat boards. There is also another classic style of framing art, which is the subject of this blog post today, the bottom-weighted mat board.

What Is a Bottom-Weighted Mat?

A bottom-weighted mat board simply means that the bottom border of the mat board is wider than the top border. This mat board style is common among traditional framers, as its practice has been in use since Victorian times.

While it’s not entirely clear why or how the practice of bottom-weighting mat boards began, some framing professionals suspect it started because of the high ceilings common in Victorian homes. Pictures were hung at an angle high on the wall, making it easier to view. However, tilting the artwork made it appear as though it was off balance; to correct this illusion, people began framing their artwork with a wider bottom border.

Another explanation of this mat board style is simply that the optical center is higher than that of the geometric center; in other words, where your eye is drawn is actually above the actual center of the space. It is related to the golden mean, also known as the golden ratio, a popular concept in art.

The Meaning of the Golden Mean

The golden mean exists when two quantities have the same ratio as the ratio of their sum and the larger of the two quantities, expressed as a formula:

Also related to the Fibonacci sequence and the golden spiral, which uses the golden ratio as its growth factor, the golden mean has been used in art and architecture as well as in math. Piet Mondrian’s famous Composition in Red, Blue and Yellow — and in fact the many works based on this theme — exhibit the golden ratio, as does da Vinci’s The Last Supper. Artists began basing their work off this concept, believing it created art that was more aesthetically pleasing.

This pattern has been found in nature, too, which makes it all the more fascinating: the seeds on pine cones follow this spiral, as do the smallest seashells and the largest galaxies. Everywhere you look — under the sea and up to the stars — you can find an example of the golden mean.

Using the Golden Mean in Bottom-Weighted Mats

The golden mean is great for creating artwork, but how does it fit in with creating mat boards? The answer is simple: you can use the ratio, which can be expressed as 1.618, to determine the correct size of the mat board. This ratio will show you how much larger the area of the mat board should be than the artwork itself. For example, if you have artwork that is 8 x 12, simply multiply the length and width by 1.618 to determine the size of the mat board.

Then, to determine the bottom width of the mat board, you need to find the optical center. To do this yourself, you can use a piece of paper as big as the mat board.

1. Place the print (or a sheet of paper the size of the print) in the top-left corner of the temporary mat board.
2. Measure to find the vertical and horizontal middle of the remaining mat board, i.e. the mat board not covered by the print.
3. Use a straightedge to draw a line from the right side of the board where the drawn horizontal line ends to the bottom left-hand corner of the artwork. Where this line intersects the vertical line is where the lower right-hand corner of the print should be.
4. Once you’ve positioned your artwork, you can measure how wide the bottom border should be.

This method may not look “right” with all artwork, and some may say that the mat board is too wide or the bottom border too big. Play around with these methods — and the golden mean — to see what kind of bottom-weighted mat board works best.