No matter how good your product is, if the packaging is done right, then the product is more likely to fail. The same is the case with glass packaging. If the glass perfume bottle has a poor appearance or has structural defects, it will fail to appeal to customers. To avoid glass defects the manufacturer should have ample knowledge about them.

This blog contains information about various defects in glass bottles and containers. Let’s read more about glass bottle defects that cause faulty appearances and structural issues.

Glass Defects in terms of Finishing

Glass defects in terms of finishing can be categorized into several types. Although there are plenty of finishing defects, some of them are listed below:

  • In bent or crooked finish, any area of the glass gives a crooked or bent appearance. There are plenty of reasons for this defect, among which the most common is the extremely high heat of machine equipment. Using a cooling nozzle can remedy the defect.
  • When the finished glass has pieces of glass broken out of it or it has cracks, then this defect is known as a broken finish. A common cause of this defect is mishandling of the finished product.
  • When the finished glass has pieces of glass broken out of it or it has cracks, then this defect is known as a broken finish. A common cause of this defect is mishandling of the finished product.
  • When the finish of the glass has large bubbles trapped inside, it refers to a blistering finish.
  • When the glass bottle has an incomplete finish at the top, thread or bead, it is known as an unfilled finish.
  • Seed finish, as the name indicates, has small seed-like bubbles in the finish of the glass.
  • Glass defects in finishing, which give the glass a saddle-like appearance, are called saddle finish. It appears in the form of a dip or slope.
  • In neck ring seam defects in glass, a fin or seam of glass is seen lying from the sides or top of the glass bottleneck.
  • Checked finish refers to defects in a glass bottle that appear as a light surface crack. This defect is visible in the threads or the middle of the finish.
This Photo by Unknown Author is licensed under CC BY-SA

Neck Defects

Neck defects are also known as hollow defects. These glass defects usually occur as a depression in the glass thickness in the neck of the glass bottle. Below are some types of neck defects in glass:

1.Pinched Neck

When the neck of the glass bottle appears to be pinched or pushed, this type of glass defect is called a pinched neck.

2.Long Neck

When the glass bottle’s neck is stretched longer than it should be, it is called a long neck defect.

3.Dirty Neck

In case of dirty neck defects in glass, the glass bottle’s neck is scaly. This scaly appearance gives it a dirty look.

4.Danny Neck

When a small surface section of the glass bottle is torn from the neck area, it refers to Danny’s neck. Such defects in glass are also called tears in the neck.

5.Bent Neck

In bent neck glass defect, the glass bottle’s neck is tilted to one side, giving it a deformed shape.

Body Defects

Wash BoardsIt appears as waves of horizontal lines or folds. Usually, it appears on the side of the container.
Bruise ChecksShallow and fine checks on the side of the container are known as bruise checks.
Letter ChecksWhen small fissures or cracks intercept the embossing on glass bottles, it is called a letter check.
Dirty WareGlass bottle defects, which cause the container to have dirty carbon deposits, are called dirty ware.
StonesStones refer to the appearance of small pieces of batch materials in the glass. Such glass defects happen because of a poor melting process.

Base Defects

The base of the glass bottle might have certain defects as well. These defects have been classified into the following types:

1.Thin Bottom

In this glass defect, the base of the glass bottle is thinner than specified.

2.Swung Baffle

This refers to the displacement of the baffle mark at the bottom of the base. In this glass defect, the baffle marks swing to one side instead of being at the center of the bottom of the glass container.

3.Oil Marks

In this type of base defect, strings of small bubbles appear at the bottom of the container,

Oil accumulation is the major cause behind such defects in glass.

4.Base Leaner

Unlike other glass bottle defects, this makes the glass bottle unstable; why?

Because it causes sagging of the bottom, making the bottle unstable to stand on a flat surface.

5.Wedged Bottom

When the base of the bottle has a localized thick area on one side, it refers to a wedged bottom. Thus, a glass defect is also called a heel tap or slugged bottom.

Shoulder Defects

Sunken Shoulders
An appearance of an unwanted depression around the shoulder is known as a sunken shoulder defect. This glass defect affects the filling capacity of the bottle or glass container. It makes the overall product look bad in appearance.
Thin Shoulders
If any shoulder of the glass bottle is thinner than the other, this is called a thin shoulder defect.
Shoulder Checks
In this defect, the glass bottle has surface cracks. These cracks are wavy or straight. They do not pass through the entire thickness of the glass bottle. Glass bottles with this defect are vulnerable to breaking after filling.

General Defects

The following defects in glass come under the domain of general defects:

1.Structural defects

Internal stresses in the container lead to structural defects. Such defects in glass are the result of a poor annealing process.

2.Stuck Ware

When a rough piece of glass is visible from the external surface of the container, it is called stuckware.

3.Fire Cracks

Small cracks that are the shape of short hooked crescents are called fire cracks. Fire cracks penetrate into the surface of the glass.

4.Sand Holes

Poor grinding of raw materials causes sand holes. These appear as rough spots on the polished surface of the glass.

Why select Gozone for Flawless Glass?

1.10 Years of Industry Experience:

Suppose you are looking for a glass bottle manufacturing company that produces flawless glass packaging. In that case, Gozone is the best option. With over a decade of glass manufacturing experience, Gozone is completely aware of all the glass defects and the remedies to avoid them.

2.Professional Quality Control Team:

The top-notch machinery and the skilled team of structural engineers and product designers make sure that all the finished glass bottles are perfect. So, suppose you want to lead your competitors in flawless glass packaging.

In that case, Gozone is the best glass manufacturing company to partner with. To make sure that clients get the best desirable products. Professional quality control team at Gozone makes sure that customers get best products


Good packaging and customer satisfaction go hand in hand. Perfect packaging is the one that does not have any defects in it. Therefore, for perfect glass packaging, you should partner with a glass manufacturing firm that is an expert in the field.

Gozone is the perfect partner for glass packaging. They provide you with flawless packaging that will attract more customers and help your brand achieve a competitive edge over its competitors.