Visit for your ultimate packaging solution.

Knowledge Base

What is Window Patching and Why it’s Used

Window patching is a technique that incorporates a window film on a carton or any other product packaging serving a dual purpose.

The window provides a glimpse of the product. It is often to tease a product, creating excitement within the customer, therefore naturally enhancing their unboxing experience. The decision to add a window film patch will naturally, depend on the nature of the product.

Exterior look is the next priority as the quality and integrity of the consumable product will assume higher priority.

Window Patching Films

Aside from paperboard, plastic is one of the most common materials for packaging, especially polyethylene terephthalate (PET) and polyvinyl chloride (PVC) plastics.

PET film is molded into the required shape followed by a drying process for enhanced resistance. The strong reinforcement provided by PET makes it tamper-proof, hence resulting in good resistance to the elements. Companies often use window packaging film for food packaging and beverage bottles.

PET plastic is lightweight, which in turn may be prone to scratches, but yet sturdy enough to combat exterior pressure and helps safeguard the contents within. It is also a safe option for storing foods, as well as a popular choice for electronics, retail, and other consumer products.

PVC film offers a more durable exterior and a superior damage resistant surface. In other words, becoming extremely resistant to tampering and natural elements. However, exposure to UV rays may result in degradation over time causing odor and water ripple. It is a less environmentally friendly option and isn’t a suitable choice for food packaging.

Other Films

  • Polypropylene is the most common material to pack candy, snacks and baked goods.
  • Glassine is for high grease products.
  • Polyethylene is for frozen food products.
  • Polyolefin is a shrink film for pizza and boxed candies.
  • Foil lamination is ideal for light and air sensitive food products.

The Window Patching Process

At the heart of the process is a window patching machine. It could be one from a leading manufacturer Heiber + Schröder or a specialist window patching machine manufacturer Kohmann.

The machine will apply windows from a reel using a specific plastic film (PET, PVC, etc…). Packaging cartons first travel through the reel at a rate of approximately 375m/min. Through the process, machines introduce films into paper packaging through electromagnetic energy.

Depending on the type of machine being used for the window patching, typically, the plastic film will stick instantly to the packaging material without any drying time. It is ready to package instantly once it is released from the machine.

For other printing finishing options, you can check out: Embossing and DebossingSoft Touch Coating & LaminationFoil Stamping, and Spot UV

About author

Mark Velarga is PakFactory's Director of Digital & Content Marketing. He writes about all things related to design, business and technology and how it serves value to customers, business owners, packaging designers and industry experts. Connect with him on Linkedin.
Related posts
Knowledge Base

Sustainable Packaging and How it Affects Your Business

Knowledge Base

Raster vs Vector: Which to Use for Packaging?

Knowledge Base

Why are Consumers Obsessed with Unboxing Videos?

Knowledge Base

Minimalism: Going Green with Minimalist Packaging Design

Sign up for our Newsletter and
stay informed