I went to a metal fabrication company and got them to do it out of stainless and etch 1/2-3" in lines to it. Sort of like a long, flat EZ Hem gauge.
Edit: actually a stainless ruler of any kind would kind of work. As soon as I posted it, I was like...meh, I use a yardstick for the flat ones, too. My fabricated one is specifically meant for bridal wear due to length and weird non-curveish curve. Which is funny when I got to thinking about it....it's basically my 60: steel ruler with lines in it.
Lot of design rulers are of a specific width. One yardstick is 1 1/8 and my 60" ruler is 2".