How to Scale a Wall
Early in my sign painting career, I was given the formula for developing a scale for anything that I wanted to transfer to a larger size. I was told to "take the big number and divide it by the small number". I have never forgot the formula and I use it quite frequently, especially for murals.
Since I am better at art than math, I need visuals to make sense of math. For those of you who have similar math skills, I will give a quick visual guide below on how to scale anything in the future. For those who think with both sides of your brain, this will most likely already be easy for you, if so, skip to the bottom of the page.
Let's say someone hands you a napkin sketch with a logo on it, and wants to enlarge it to a certain size. How do you calculate the scale of all the elements of the sketch? Take the ellipse example below.
As long as you have established one overall size in inches, you can calculate all the other sizes with the scale factor. The scale factor is derived by dividing the big number (in inches) by the small number (in centimeters). In this particular instance we were given a final size of 96" for our enlargement.
In order to find the scale factor for all of the rest of our measurements, we need to figure out the scale factor. In order to find the small number of our formula, I need to use a measurement that is based in increments of 10. A centimeters ruler usually works the best. Now measure the known dimension (big size in inches) with the centimeter ruler (small number in cm). That would be 96 inches divided by 18.9 centimeters, which gives us a scale factor of 5.08 (see image below).
Now we can measure anything on our napkin sketch with the centimeter ruler and multiply that by our scale factor, and come up with the enlarged size in inches. For instance. if we need to enlarge the sketch up to 96", what will the height of the logo be in inches?
We simply measure the overall height in centimeters and multiply that measurement by the scale factor...8.6 cm x 5.08 = 43.688" (see below)
We came up with 43.688" tall. This brings up another question...how to convert the .688" decimal to something we can find on a ruler? Simply look the decimal you derived up on a decimal equivalent chart, and you can find the ruler measurement. The decimal of .688" is closest to 11/16 from the chart below.
Ok, now that we have that figured out, let's see how to do it on a real world project. We took an overall length measurement of our Roger Reiman wall of 50' - 2". In order to find our "big number" from above we need to convert the overall size to inches. 50' x 12 = 600 inches, plus the 2" inches = 602" wide.
Here is where a straight on photograph of the wall is very helpful. I shot a picture of our wall during our visit. I could just print out the wall image, and that would be similar to my napkin sketch from the above example. I would then just measure the overall width in centimeters and the divide it into 602". But I plan on doing my design work in Adobe Illustrator®, so I will calculate my scale factor using that program.
I opened a new Adobe Illustrator® document and set the units to centimeters. I then placed the Reiman Wall photograph into the Illustrator® document. In order to measure the wall and calculate the scale factor, I create a rectangle the same size as the wall. I can then use Illustrators measuring tools to determine the rest of the sizes by multiplying by the scale factor.(see image below)
Next up, I will talk about how we determined what size mural to paint on this particular wall. We will also discuss the wall condition and mural placement.
