Every zipper has a different length. While zippers are generally measured from one end to another, the truth is that every type of zipper is measured in different ways.
Discussed below are the common methods used to identify the right length of zipper. You can use these methods to get and determine the correct measurement of zipper you need for any sewing project you have. Make sure you zip up the zipper fully before you start measuring it, whatever the type of zipper in question might be.
Measuring the Length of an Open Ended Zipper
The length of standard open ended zippers is measured starting from the upper end of the zipper slider down to the tip of the open part with the forth head tape excluded. Accidental inclusion of the forth head tape might result to getting a zipper with a length that is relatively shorter than what you really need or like.
Measuring the Length of a Close Ended Zipper
In the case of a standard close ended zipper, the length gets measure from the zipper slider’s upper tip down to the bottom stop’s end without including the forth head tape and back head tape. Once again, the incorrect inclusion of the forth head tape or back head tape will give you a zipper with a shorter length than what is required.
Measuring the Length of a Two Way Open Ended Zipper
The length of a standard two open ended zipper must be measured starting from the zipper slider’s upper tip down to the reinforce tape’s bottom tip to the open part’s end with the forth head tape excluded.
Measuring the Length of a Two Way Close Ended Zipper
There are two categories of two way close ended zippers and these are O shape and X shape. Both of these types feature double zipper sliders. Their main difference is that there are two bottom stops in the former where the sliders get installed in head to head relation. The latter, on the other hand, feature two top stops where the sliders are found in bottom to bottom relation.
For standard O shape two way close ended zippers, you need to measure their length from one bottom stop’s end to the other’s end. The forth head tape and back head tape shouldn’t be included.
For standard X shape tow way close ended zippers, you can measure the length starting from one zipper slider’s upper tip to the other’s upper tip. Again, this doesn’t include both the forth head tape and back head tape.
Consider Allowable Tolerance
Zippers might have natural tolerance due to the different factors such as the involved techniques that were used, the machines’ operation speed and the zipper chain’s tensility during the process of manufacturing. The tolerance is generally proportional to the zipper’s length.
If you are unsure regarding the specific zipper length you need, you can get zippers by specific length at https://www.zippershipper.com/zipper-chain-by-the-yard made especially for both tailors and DIY specialists.