Is Glassine Waterproof?

Glassine or glassine packaging is widely known for its smooth, glossy finish and its several protective qualities. But is glassine waterproof?

Is Glassine Waterproof?

No, glassine is not waterproof. It is water-resistant to a degree, meaning it can handle minor moisture exposure like humidity or light splashes but will not withstand being fully submerged in water or heavy water exposure. The material's non-porous nature gives it some protection against moisture, but it is not designed to be completely impervious to water.

For instance, if a glass of water spills on glassine, the liquid would gradually seep through. Nevertheless, glassine’s non-porous nature allows it to withstand minor moisture exposure, such as humidity or incidental splashes, making it a versatile choice for various applications. 

What Is Glassine Made Out Of?

Glassine is made out of wood pulp that has undergone a supercalendering process. This process involves pressing the paper between rollers to make it very smooth and glossy. The intense pressure and heat during this process align the fibers closely, which yields the paper's translucent, non-porous, and grease-resistant properties. This treatment also gives glassine its characteristic smooth, waxy feel.

READ MORE on what glassine is- we talk about everything you need to know about it here!

The Characteristics of Glassine

Why should you choose glassine bags? If you value and prioritize these qualities for your next packaging, glassine might be your best bet. 

Glassine is translucent

Glassine allows light to pass through, making it suitable for protecting delicate items without completely obscuring their visibility.

Best for: Glassine is perfect for protecting art prints or clothes during storage or transport. Its translucency allows the beauty of the artwork to be visible without removing it from protection, minimizing handling damage while still showcasing the print.

Glassine is grease resistant

It repels grease and oil, which is useful for packaging food items or protecting surfaces.

Best for: packaging baked goods such as cookies, pastries, or doughnuts. It helps keep the grease and oil from these foods contained, ensuring they don't stain other items or surfaces they come into contact with.

Glassine is pH neutral

Glassine is typically pH neutral, meaning it won’t introduce acidity to the items it encloses.

Best for: Glassine being pH neutral is essential for storing antique books or documents. This quality ensures that it won’t contribute to the deterioration or acidification of sensitive paper over time

Non-Porous

While not fully waterproof, glassine resists moisture to some extent.

Best for: Its ability to resist moisture, even though it's not fully waterproof, makes glassine suitable for envelopes used in philately (stamp collecting). It can protect stamps from humidity and minor splashes of water, thus maintaining their condition and value.

Other Common Uses For Glassine:

• Photography: Historically, glassine was used for storing negatives and as interleaving paper in photo albums.
• Crafts and DIY: Artists and crafters use glassine for various projects due to its versatility.

Alternatives For Glassine

If you need stronger or similar water resistance, consider using:

• Polyethylene Bags: These are fully waterproof and commonly used for shipping and storage.
  
  
• Archival Polyester Sleeves: For long-term photo storage, archival polyester sleeves provide better protection against water and other environmental factors.

FAQs

No, glassine paper is not completely waterproof. It is water-resistant to some degree, which means it can resist water penetration to a certain extent but will not completely block water.

Glassine paper is less water-resistant than waxed paper. Waxed paper has a coating that makes it more effective at repelling water, whereas glassine is only treated to be greaseproof and somewhat water-resistant.

Yes, glassine can be treated to enhance its water resistance. Additional coatings or laminations can be applied to make it more waterproof, although this might alter its other properties.

Considering its water resistance, glassine is best used for packaging dry goods, protecting photographs, archival storage, and as a liner in baking. Its semi-transparent nature and grease resistance also make it suitable for wrapping fatty foods.

The duration glassine can resist water exposure varies based on the thickness and specific treatment of the paper. Generally, it can handle short-term exposure to moisture, but prolonged contact with water will eventually lead to damage.