Corner Radius

What does "corner radius" mean and how is it measured?

A corner radius describes how rounded the corner is for a rectangle or square label. To understand exactly how the corner radius is measured it will help to revisit some geometry that you no doubt learned (and maybe later forgot) in high school math class.

It may be completely obvious to most people, but it is worthwhile stating here that a corner radius will only apply to squares and rectangles. Ovals and circles have no real corners, so they will not have a corner radius measurement. A rounded corner on any rectangle is actually an arc of a circle. So, imagine that you completed the arc to create a circle that included the corner arc.

Like all circles, this circle has a radius. The radius of a circle is the distance from the midpoint of the circle to the circumference.

So the corner radius measurement used is the actual distance from the center to the circumference of this “imaginary” circle that includes the corner arc of the square or rectangle.

If I have lost you, don’t worry. You just need to remember this:

As you can see from the diagram above, the larger the corner radius measurement, the more rounded the corner. So a 1/4” (0.25”) radius is much more rounded than a 1/16” (0.0625”) radius.

If you want to see exactly what the corners will look like for your rectangle or square label, then just ask us for a die line. We will be happy to email you a PDF of the die shape so you can see for yourself.

(Peter Renton)