Inkjet Printing on Glass: Do’s and Don'ts

Versatile, long-lasting, and visually appealing, glass is one of today’s most popular packaging products. 

Used to package food, beverages, pharmaceuticals, personal care products, and more, glass packaging is not only highly effective at keeping products fresh but also gives products a premium appearance on the shelves. Of course, glass packaging can only appear on store shelves if it is carrying the required codes and markings. 

Whether your company uses glass to package beer, OTC drugs, makeup, or another type of product, traceable codes are a must. Often required by federal agencies, state laws, and distribution network policies, traceable product codes take a number of forms, including:

• Expiration dates / filled-on dates
• Lot codes
• Batch numbers
• Bar codes
• QR codes

With the help of these markings, companies are able to more successfully perform recalls, ensure accurate shipping, and inform customers of when products are safe to use and consume. 

To apply these codes, companies of all backgrounds frequently turn to inkjet printing. Inkjet technologies—such as continuous inkjet (CIJ) printers and thermal inkjet (TIJ) printers—are valued for their reliability, results, and compatibility with various forms of glass packaging.

However, inkjet printing on glass can be an intimidating process if you have never done it before. If you are new to the world of product coding, keep reading to learn how you can make sure that your applied codes are sharp, machine-scannable, and durable enough to survive the entire product lifecycle.

Best Practices When Inkjet Printing on Glass Packaging

Inkjet printing success hinges on a few factors. For codes to appear sharp and remain intact throughout distribution and personal use, companies must use the right combination of hardware and ink to fit their applications. 

Whenever you are printing on glass, follow these best practices in order to avoid misprints and smeared codes:  

1. Use a Printer That Is Compatible With Your Surface Type

No matter what kind of material you are planning to print on—glass or otherwise—you must use marking hardware that is compatible with your substrate. While the majority of CIJ printers are compatible with glass, in order to work on glass, many TIJ printers are limited to perfect lab conditions with no environmental factors. TIJ printers are only able to print on porous materials such as cardboard and paper in any manufacturing environment. Naturally, the first step toward glass printing success is to use a glass-compatible printer. 

Along with material compatibility, it’s important to think about what kind of surface you will be printing on. For instance, are you going to be printing on a curved bottleneck, or will you be printing on a flat surface? 

If you are printing on a curved surface, a CIJ printer like the DuraCode Touchscreen will generally be a better fit than a TIJ printer due to the longer print distance allowing the print to be legible on a curved surface. While some TIJ printers are able to print on curved surfaces, the majority are better suited for marking flat surfaces.  

2. Choose an Ink Formula That Will Adhere Well to the Material

Along with choosing the right hardware, proper ink choice is essential to glass marking success. 

For printing on glass, you will want to find a solvent-based ink. Broadly speaking, solvent-based inks have faster drying times and better adherence to non-porous materials than water-based inks. You will also want to factor in any challenging facility conditions, such as:

• High humidity 
• Condensation presence
• High or low temperatures
• Alcohol presence

Each of these elements can cause unforeseen problems if not accounted for. Fortunately, InkJet, Inc. offers specialty formulas designed to compensate for these issues. These formulas are also available in multiple colors, allowing users to select inks that will appear sharp on different colored glass. 

What To Avoid When Inkjet Printing on Glass Packaging

Along with best practices come a number of practices that you should avoid whenever inkjet printing on glass. Follow these two tips to ensure code legibility consistently:

1. Do Not Place Codes On Surfaces That Will Make Direct Contact With Other Packaging

Even if your chosen ink formula has excellent glass adherence, it’s important to minimize the amount of physical contact that any code is exposed to. You should make sure that any surface you’re printing on does not make direct contact with other objects or packaging. 

For example, if you are printing on glass bottles that will end up in a pack, do not print on a side that will rub against other bottles or cardboard packaging. Instead, printing on the bottle’s neck or bottom will be a better choice. 

2. Do Not Print on Transparent Glass Without the Right Line Accommodations

Many line setups are not established with transparent surface printing in mind. For example, lines that use standard through-beam sensors in order to trigger printing will likely struggle when printing on transparent glass. 

To ensure that your printer will recognize transparent glass, we suggest investing in retro-reflective photoelectric sensors. As compared to standard through-beam sensors, retro-reflective systems can more accurately detect the presence of transparent materials, boosting overall printing accuracy. 

Need Help With Inkjet Printing on Glass? Talk to an Expert at InkJet, Inc.

Inkjet printing has been a go-to glass marking technology for well over 50 years. With the right inkjet printer and technical knowledge, companies of all sizes and specialties can mark glass packaging with speed and reliability. If you want to begin inkjet printing on glass, InkJet, Inc. can help you get started. 

Offering 30 years of industry experience and a wide range of printing solutions, InkJet, Inc. has everything you need to achieve printing success. Contact us today to learn more. 

For personalized help with inkjet printing on glass materials, contact us online today or call 1(800) 280-3245.