Reliable Glass Bottles, Jars, Containers Manufacturer | Roetell

Types of Glass Defects and Roetell’s Remedies

Investing resources and months of research into developing a product only to have an unresponsive market can be frustrating. Sadly, this is often what happens when a key factor like packaging is overlooked. This is why you need to know the types of glass defects and how these defects may affect your brand if you make use of glass containers.

In this post, we’ll discuss the types of glass defects, as well as glass bottle inspection and remedies. With this, a glass defect will never get in the way of your customer’s satisfaction or jeopardize your business’s possibilities.

Types of Glass Flaws and Defects

Glass container defects may be grouped into 6 categories based on where they occur.

Finish Defects

  • Seam under finish: A seam of about or greater than 5 mm on the joint between a glass bottle finishing mold ring and blank mold.
  • Offset finish: A finish formed out of alignment vertically or horizontally. Offset finish may impact sealing and thus product quality. It could also cause breakage along the closure bridge.
  • Split finish: A crack across the top surface of a glass container extending from the top down towards the neck. If the glass bottle has a split finish, users will have a potential leak on their hands.
  • Folds on the finish: Vertical or horizontal folds outside the glass container. This defect may also be referred to as wrinkles or lap marks. Often, this aesthetic flaw cannot be overlooked in glass containers intended for beautification.
  • Crizzled finish: A finish with numerous fine surface fractures.
  • Glass trimmings on exterior finish: A thin protruding rim of glass (greater than 2 mm) around the finish. Glass trimmings on exterior finish may cause faulty corking. 
  • Chipped finish: A bottle finish with a small section broken or chipped off.
  • Seeds: Tiny bubbles in the glass and may be found on the sidewall and base as well.
  • Blisters: Air or gas-filled cavities within glass containers. Blisters are just like seeds but larger.
  • Unfilled finish: An irregular finish; certain spaces are not filled, i.e., there are missing pieces of glass. These spaces affect vacuum filling, which may cause leaks and boost content deterioration.
  • Stones: Small pieces of unmelted glass trapped in finished glass.

Neck Defects

Shoulder Defects

  • Shoulder checks: Surface cracks that do not pass through the entire thickness of the bottle, usually straight or wavy. Shoulder checks increase the risk of bottle breakage after filling. 
  • Sunken shoulder: Unwanted depression around the shoulder. A sunken shoulder may reduce the filling capacity of the affected container. It also gives an overall bad appearance of the container—not what you want for your products.

Sidewall and Body Defects

  • Bird swing or bird cage: A thin string of glass extending across the inside of the bottle or container.
  • Internal Blisters: Blisters within the glass walls.
  • Stuck ware: A rough, sharp, or cutting edge on the body of a glass container. Stuck ware may damage secondary parking and cause injury to your workers. 
  • Burrs: Similar to stuck ware but found along the mold seams.
  • Dirty ware: Similar to a dirty neck. Dirt or carbon deposits are usually to blame.
  • Deformation: Glass container has a shape anomaly. A deformed container may affect labeling and secondary packaging. Plus, a deformed bottle is bad for brand integrity.

Base and bottom defects

  • Chain marks: Prints at the base of the bottle, usually due to contact with the conveyor belt immediately after manufacture.
  • Deformed bottom: The bottle base has a deformity, e.g., the center is protruded instead of being sunken. A glass container with a deformed base will be unstable i.e., it won’t stand straight.

Other Defects

Other defects in glass containers include cords, internal marks, uneven distribution, and out-of-shape ware, among others.

Several defects can occur during the manufacture of glass and glass materials.

Glass Bottle Inspection and Remedies

If you’re in the packaging industry, you’re likely familiar with the Empty Bottle Inspection for glass.

Empty Bottle Inspectors (EBIs) have been in operation for about three decades. EBIs run a comprehensive check on empty bottles. They evaluate the glass wall thickness, defects, and the inclusion of foreign materials in glass—which are the general concerns of producers. 

Roetell’s Quality

Being able to detect glass defects is a handy skill if your company uses glass. But, with Roetell supplying your glass bottles, you’ll never have to detect a defect. We offer you reliable glass bottle production, inspection, and a robust, stress-free package.

Discussed below are some of the services your brand will enjoy from us.

Technical Support from Inception to Delivery

We recognize that each business is unique and, as a result, we never approach with a one-size-fits-all mindset. Instead, we consult with your business to understand your unique needs and then manufacture bottles tailored to meet them, keeping you in the loop every step of the way.

Assured Quality

Our glasses are without defects as they are manufactured by passionate experts who work zealously to ensure that your business gets the perfect glass it needs. Split finishes, deformation, blisters, cords, crumbles, and other defects are simply not a possibility when working with our team.

All-Round Checks

We understand that, as a business, you have other production activities to worry about. So, we take away the worry of uncertainty with your glass containers. We run quality checks and finish checks to ascertain that the glass is smooth and flawless. But beyond that, we also do physical and volumetric checks. Before a container is released from our glass plant, it’s inspected for functional standards set to meet your business needs.

Exact to the Letter

Regardless of your industry, you can rest assured that you’ll get exactly what you requested. We are a reliable glass manufacturer that believes beauty starts with the details. So, we see to it that every cut made brings us closer to your business’s perfect glass.

Extensive Experience

Roetell has been providing quality glass packagings for over 35 years. We have a team of experienced professionals whose focus is to safeguard quality and supply bulk glass products that meet your brand’s specifications to the letter.


The quality of your product packaging is as important as that of the content. Glass defects dictate how your brand will be perceived and how reliable your products will be.

Glass containers are versatile, classy, and timeless, and with a reliable company like Roetell supplying yours, you’re a step closer to unrivaled customer satisfaction and sales. You can contact us for the best glass containers and bottles to package your products.

Reliable Glass Bottles, Jars, Containers Manufacturer | Roetell