We often hear from folks who have some bottles and jars but need some new lids in order to re-use or re-purpose them. This post will provide guidance on how to measure glass jars and lids to determine what size lid the jar needs, or vice versa. This post primarily addresses how to measure a jar in order to determine it’s finish measurements. If you need help deciding which type of lid/jar combination may best suit your needs, you will want to check out A Guide to Commercial Canning Lids or How to Choose a Canning Lid. If you are planning to sell your product, we recommend Food Processing Resources to help you on your journey.
The specific measurements (all of them!) of the jar finish and of the lid finish matter. Be sure you are choosing a lid compatible with your jar by browsing from the “Accessories” tab of the jar in question. We link them in this way to avoid order errors. If you need to verify, be sure to contact our customer service team before ordering.
Different Jar Finishes
First, it’s important to know that these are the two primary types of containers and closures currently used in food packaging.
Continuous-thread (CT) is the Mason-style closure mechanism where the jar and lid are both threaded in one continuous bead around the entire circumference of the opening; also referred to as “screw-on”. The skirt (the part that comes down around the mouth of the jar) of these CT lids can vary. Generally, typical mason jars have a 70/450 finish and would require that size of lid. However, there is also a “short skirted” CT finish; with a 70/400 finish. We show examples of these later in the post.
Lug is the closure system where the container has multiple threads and the lid has an equal number of lugs or tabs that grip the corresponding threads; also known as “twist-off” closures.
