Lets say you want to turn a 1/2″ hem. Now you could bring along your ruler and measure along the way, or if you’re feeling particularly reckless you could eyeball it. But there is an easy and accurate way to mark your hem for pressing.
First off, double your hem measurement. So, if your hem is 1/2″, your measurement is now 1″. This is where a C-thru ruler will come in handy. C-thru rulers have measurements running in both directions, so it is easy to mark long parellel lines. The line in the center of the rulers marks 1″. Line up the ruler to the 1″ chalk a line in place.
Now when you head to your iron, simply fold the edge of your fabric up to that line and press for a perfect 1/2″ hem!