WHAT IS GLASSINE?

• Glassine is a smooth and glossy Paper product made from Hardwood trees such as aspen, oak, birch and gum.
• Production begins in the same manner as many other wood pulp-based products, by debarking and chipping the tree and cutting the logs into pieces for pulping. While standard paper can contain some lignin – the second most prevalent constituent of wood after Cellulose – it must be removed entirely from the pulp when making glassine as it can cause it to discolour over time.
• Once separated, the pulp can be bleached or dyed if desired. It is then pumped through a wire cloth to create the fibres. Calendaring is the next step in all paper production, however, glassine is put through the process multiple times, known as supercalendering. This involves feeding the paper through alternating hard and soft rollers, which apply heat or cooling, pressure, and friction to homogenise the fibres and buff the surface.
• The supercalendering process also makes glassine acid-free and pH-neutral. It is therefore resistant to changes in its structural properties when in contact with other chemicals or structures.
• Due to its multiple unique, resistant properties, glassine has traditionally been used for release liner, which holds stickers and labels. It also has a history of being utilised to protect stamp collections, books and art. As demand for sustainable materials has risen, its applications have expanded to include polybag alternatives, food wrap and beauty packaging.
• Glassine is naturally transparent but it can be dyed. Other finishes include: rotogravure, flexo, offset and digital printing. Embossing is also possible, however, the smooth finish makes it a tricky process.
• As an uncoated paper product, glassine is recyclable at the kerbside, biodegradable and compostable.