I opted for a grey duck canvas because it's flexible, yet heavy enough to lay flat and thick enough write on with Sharpie without soaking through. I had Mama Z do all the sewing, so she hemmed the edges and made the entire thing 12" wide and roughly 78" tall (don't forget to leave enough extra to sew a loop for the dowel rod). Because we have plush carpet in the nursery, I started the ruler at 6" so I could hang it off the ground to avoid dragging.
I first used pencil to mark my lines. The lines marking a foot are 4" long, the quarter-inch lines are 3" and the other lines are 2" long. I recommend using a square or triangle to make sure all your lines are level. I put pieces of masking tape on the triangle to mark the various lengths so I didn't have to measure every single line while trying to keep things level.
The numbers were printed out on regular text paper. (I opted for Bauer Bodoni if any of you design nerds care.) In order to not smear graphite or charcoal all over the fabric, I held the printout up against a window and used a pencil to scribble around only the edge of the numbers on the back side of the paper. Then when I traced around the numbers (on the printed side), only the necessary amount of graphite was transferred onto the fabric.
From there, I used black fabric paint to fill in the numbers. This was a bit time consuming and required two coats, but I'm super happy with how it turned out.
The lines were also painted on using black fabric paint. In order to keep my lines the same width, I cut a 1/8" wide template in a piece of cardboard. This part bummed me out because I used two different techniques and half the lines on the ruler turned out so much better than the other half. I started off dabbing my paintbrush inside the cardboard template. The lines turned out a little jagged. I found making smooth brush strokes through the opening made things look a lot cleaner. Gah, live and learn.
As you can see... the line quality is quite a bit different. Poo.
I used a very thin dowel, painted it black and hung the whole thing with thick, black string. A 3M adhesive hook worked great because it won't damage the door when I take it down someday.
Until Brody is old enough to stand up against the growth chart, I just took his measurements from doctors appointments and added them on with Sharpie.
Overall, I'm happy with how it turned out and it looks great inside Brody's room. However, I feel like Brody will outgrow the 6' 3" growth chart by the time he's a teenager at the rate he's going.