Confused by Aspect Ratio?

Have you been confused by encountering the term “aspect ratio” when looking at chainmaille weaves, or discussions of jump rings?  I have too!  Aspect ratio is a simple concept that can be helpful, incorrect, and is almost always confusing and frustrating.
 

 

What is Aspect Ratio?
Aspect ratio is the inner diameter of the ring, divided by the thickness of the ring.
 

 

Wait, I don’t understand?
A jump ring is generally described using two numbers.  The first is the thickness of the wire used to make the jump ring.  This is called the gauge.  The second number is the diameter of the jump ring.  Here at UnkamenSupplies jump rings are measured using ID, or Inner Diameter.  Our commercial rings are measured by their OD, or Outer Diameter.  You can read about the difference in these two measurements here.
 

 

So, what does that mean in regard to Aspect Ratio?
Aspect ratio isn’t a magical number.  It is a fraction, or ratio.  That means that it is a measure of the relationship of two other numbers.  When you look at aspect ratio you are looking at the relationship between  the inner diameter of the jump ring(in millimeters) and the thickness of the jump ring(in millimeters).
 

 

FRACTIONS ARE SCARY!!!!
I promise they aren’t that bad.  I’ll even give you a tip that will make them REALLY easy!  I’m sure that you know that when you divide something by 1 it doesn’t change.  For example 4/1=4 , 5/1=5 , and 567.89/1 = 567.89
 

 

So?
18 gauge wire is 1mm thick!  That means that the aspect ratio of an 18 gauge ring is its ID(inner diameter).  If you know the aspect ratio of a weave but don’t know what size rings to use, 18 gauge is really easy to figure out.  Let me give you an example.
 

 

Anne would like to make a new weave.  She’s never tried it before and it says it has an Aspect Ratio of 4.5.  It has beautiful pictures in the tutorial, but the author didn’t list what size rings they used.  She knows that if the aspect ratio is 4.5 she will be able to make it in 18 gauge 4.5mm ID rings.  

 

In case you’d like to see the math for that
AR(4.5) = ID(4.5) / 18 gauge(1mm) 
 

 

I thought you said it could be incorrect?  Why don’t I ever see it listed in your shop?

The aspect ratio of a chainmaille weave is generally considered to be a range of values describing the range of jump rings with which it is possible to make that particular weave.  For example, European 4 in 1 will generally work when made with rings that have an aspect ratio between 3 and 5.  In a perfect world those numbers are exact and scalable.

 

I do not run my shop in a perfect world.  In my shop suppliers sometimes give me wire that is not precisely the right gauge.  Because of this and other errors I find it to be too risky to rely on numbers for your products.  I test every weave I offer and make sure that it works in the ring size I list, plus a margin of error.  I work hard to ensure that my products never come to you in a size that “works on paper”.  My products are tested and proven.

For all the ladies out there my wife has another point to help you understand why I don’t use aspect ratio in my shop.

You know your dress size right?  Is it the same at every store?  Just like your jean size I’m sure you rely heavily on the knowledge that your dress size will be the same in every brand, and at every store.  I joke of course.  I know that sizing changes between brands, and even between different product lines.  Aspect ratio is a little bit like that.

I hope I’ve helped you understand this confusing number!
 
 

 

-Ralph

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